' 


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/B  E  R  K  E  I E  'T\ 

LIBRARY 

UNIVERSITY  OF      ) 
V       CALIFORNIA      / 


UB&ARY 


7HE    pTORY     OF    THE    1^0  C  Kg. 


POPULAR  GEOLOGY 


J.    DORMAN    STEELE,    Ph.D., 

FELLOW  OP  THE   GEOLOGICAL  SOCIETY,  LONDON,   AND   AUTHOR  OP  THE 
FOTJRTEEN-WEEKS  SERIES  IN  NATURAL  SCIENCE. 


'  Jjfy  heart  is  awed  within  me,  when  I  think 
Of  the  great  miracle  which  still  goes  on 
In  silence  round  me— the  perpetual  work 
Of  Thy  creation,  finished,  yet  renewed 
Forever. "  —BRYANT. 


REVISED     EDITION. 


A.    S.    BARNES    &     COMPANY, 

NEW    YORK    AND    CHICAGO. 


THE   FOURTEEN   WEEKS'  COURSES 

IN 

NATURAL    SCIENCE, 

BY 

J.    DORMAN    STEELE,    A.M.,    PH.D. 

Fourteei}  Weeks  iq  Natural  Ptylosopfyy,      Price,  $1.00 

Fourteei)  Weeks  iij  Cr^ernistry,  "  1.00 

Fourteei}  Weeks  ii)  Descriptive  Astronomy,    "  1,00 

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and  Problems  in  Steele's  14  Weeks'  Courses,    "         1,00 

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The  same  publishers  also  offer  the  following  standard  scientific 
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Jarvis'  Physiology  and  Laws  of  Healtfy  "  1,20 

Wood's  Botanist  and  Florist,  "  1.75 

Cl^anjbers' Elements  of  Zoology,  ".  1.00 

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Page's  Elements  of  Geology,  "  .90 

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Copyright,  1870,  1877,  by  A.  S.  Barnes  &>  Co. 

STEELES'  GEOL. 


(£77 


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PREFACE. 


rT^HE  present  work  is  based  upon  the  same  general  plan 
as  the  preceding  ones  of  the  series.  The  aim  is  to 
make  science  interesting  by  omitting  the  minutiae  which  are 
of  value  only  to  the  scientific  man,  and  by  presenting  alone 
those  points  of  general  importance  with  which  every  well- 
informed  person  wishes  to  become  acquainted.  The  thing 
is  of  more  value  than  the  name.  A  pleasant  fact  will  be 
recollected  long  after  an  unpronounceable  term  has  been 
forgotten.  Therefore,  only  enough  geologic  nomenclature 
is  used  to  make  the  study  systematic,  to  awaken  a  love  for 
the  order  of  nature,  and  to  afford  a  plan  around  which  other 
knowledge  may  crystallize. 

The  author  is  satisfied  from  his  experience  as  a  teacher 
that  pupils  take  no  interest  in  the  fossils  which  characterize 
the  various  geologic  epochs,  except  the  few  which  are  typi- 
cal, unless  they  have  access  to  a  paleontological  cabinet ; 
in  that  case,  they  learn  the  names  best  by  association  with 
the  objects.  If  any  attempt  is  made  to  name  and  illustrate 
the  fossils  of  any  group,  the  limits  of  a  small  text-book  per- 
mit but  a  scanty  selection,  which  is  of  little  value  in  the 


6  PREFACE. 

identification  of  the  fossils  gathered  by  a  class  even  within 
the  limits  of  that  group,  while  to  those  outside  it  is  useless. 
Hence  a  school  Geology  should  give  only  the  general  out- 
lines, leaving  to  the  teacher,  with  a  copy  of  the  survey  of 
his  own  State,  and  such  collections  as  he  may  have  or  can 
gather,  to  impart  the  instruction  in  local  paleontology.  The 
author  has  sought  to  develop  the  following  peculiarities : 
(i)  To  give  the  general  outlines  of  each  subject,  and  only 
enough  of  the  details  to  interest  without  burdening  the 
mind ;  (2)  to  develop  the  theories  of  the  science  thor- 
oughly, and  thus  afford  a  clear  idea  of  the  methods  of  geo- 
logic study  as  a  basis  for  future  progress;  (3)  to  give 
blackboard  analyses  of  each  subject  for  topical  recitations ; 

(4)  by  means  of  foot-notes  to  present  the  pupil  with  much 
geologic  literature,  thus  affording  the  information  and  cul- 
ture of  an  extended  range  of  collateral  scientific  reading 
which  would  otherwise  be  within  the  reach  of  few  pupils  j 

(5)  to  add  the  benefits  of  the  "  question  and  answer"  sys- 
tem to  those  of  the  topical  method  by  means  of  a  set  of 
thorough  review  questions  at  the  close  of  the  book ;  (6)  to 
lead  the  pupil  to  a  study  of  natural  objects  by  treating  very 
fully  the  stones  common  in  the  Drift,  and  thus  giving  prac- 
tical field-work  at  once  ;  (7)  to  adapt  the  book  to  all  sec- 
tions of  our  country  by  means  of  a  clear  presentation  of  the 
typical  New  York  system,  and  such  modifications  in  the 
text  or  foot-notes  as  will  enable  any  pupil  to  make  the  ap- 
plication to  his  own  State. 

It  is  hoped  that  this  book  will  render  the  study  of  Geol- 
ogy possible  to  young  persons  striving  after  self-education — - 
to  men  of  business,  whose  leisure  allows  only  a  limited  ac- 
quaintance with  books,  and  to  schools  where  the  fresh  buoy- 
ant spirits  of  youth  are  now  repelled  by  cold,  formal  state- 
ments of  purely  technical  truth.  The  author's  most  earnest 


PREFACE.  7 

desire  is  to  awaken  the  thought  and  quicken  the  imagina- 
tion of  the  pupil  •  to  lead  him  to  trace  in  nature  the  hallow- 
ing and  refining  influence  of  Divine  truth,  and  thus  to 
become  one  of  that  happy  number  who 

"  As  by  some  secret  gift  of  soul  or  eye, 
In  every  spot  beneath  the  smiling  sun 
See  where  the  springs  of  living  water  lie." 

The  author  would  take  this  opportunity  of  especially 
thanking  the  following  teachers  and  friends,  who  have 
aided  him  in  this  revision  with  many  valuable  suggestions, 
as  well  as  in  the  reading  of  manuscripts  and  proof-sheets : 
ALEXANDER  WINCHELL,  LL.D.,  Professor  of  Geology,  Sy- 
racuse and  Vanderbilt  Universities  ;  JAMES  HALL,  LL.D., 
Geologist  of  the  State  of  New  York ;  A.  H.  WORTHEN, 
LL.D,,  Geologist  of  the  State  of  Illinois ;  L.  S.  BURBANK, 
A.M.,  Scientific  School,  Woburn,  Mass.  ;  J.  J.  STEVENSON, 
Ph.D.,  Professor  of  Geology,  University  of  the  City  of  New 
York,  and  many  others  who  have  kindly  furnished  the  rich 
fruits  of  their  experience. 

The  author  takes  great  pleasure,  also,  in  acknowledging 
his  particular  obligations  to  Winchell's  Sketches  of  Crea- 
tion, Page's  Chips  and  Chapters  and  Past  and  Present 
Life,  Foster's  Mississippi  Valley,  and  Agassiz's  Geological 
Sketches.  Many  of  the  drawings  are  copied  from  nature  ; 
the  ideal  views  are  taken  from  Figuier's  World  before  the 
Deluge.  The  Scenift  Descriptions,  which  are  a  peculiar 
feature  of  the  book,  are  rhetorical  flowers  culled  from  the 
broad  field  of  geologic  literature.  The  Glossary  at  the 
close  of  the  work  is  based  upon  standard  authorities,  and 
will  be  found  useful  for  reference. 


8  PREFACE. 

The  author  would  recognize  his  obligations,  in  general,  to 
the  following  authorities : 

Manual  of  Geology DANA. 

Manual  of  Mineralogy DANA. 

Geological  Sketches AGASSIZ. 

Methods  of  Study AGASSIZ. 

Travels  in  Brazil AGASSIZ. 

Elements  of  Geology HITCHCOCK. 

The  Mississippi  Valley        ....  FOSTER. 

Our  Planet DENTON. 

Chips  and  Chapters PAGE. 

Elements  of  Geology    .        .        .  .  PAGE. 

The  Earth's  Crust PAGE. 

Past  and  Present  Life PAGE. 

Medals  of  Creation MANTELL. 

Wonders  of  Geology MANTELL. 

The  World  Before  the  Deluge     .        .        .  FIGUIER. 

Elements  of  Geology LYELL. 

Earth  and  Man GUYOT. 

Vegetation     des     Diverses     Periodes    du 

Monde   Primitif F.  UNGER. 

Recent  and  Fossil  Shells      .        .        .        .  WOODWARD. 

Man  in  Genesis  and  in  Geology  .        .        .  -THOMPSON. 

Acadian  Geology DAWSON. 

Old  Red  Sandstone HUGH  MILLER. 

Testimony  of  the  Rocks        ....  HUGH  MILLER. 

Popular  Geology HUGH  MILLER. 

State  Report  of  New  York    ....  HALL. 

State  Report  of  New  Jersey  ....  COOK. 

State  Report  of  California    ....  WHITNEY. 

State  Report  of  Illinois         ....  WORTHEN. 

State  Report  of  Pennsylvania       .        .        .  ROGERS. 

Manual  of  Geology EMMONS. 

Elements  of  Geology ANSTED. 

Siluria  (fourth  ed.,  1867)       ....  MURCHISON. 

Sketches  of  Creation WINCHELL. 

Prehistoric  times LUBBOCK. 

Manual  of  Paleontology       ....  NICHOLSON. 

Early  Man  in  Europe RAU. 

The  Popular  Science  Monthly. 


SUGGESTIONS    TO    TEACHERS. 


teacher  will  find  Dana's  Manual  of  Geology,  re- 
vised  edition,  of  great  value  for  reference  in  his  studies. 
In  the  eastern  States,  Hitchcock's  works  are  of  especial  ser- 
vice. The  geological  report  of  one's  own  State  is  essential 
to  furnish  local  information,  and  to  enable  the  teacher  and 
pupil  to  identify  the  fossils  they  may  gather.  Geology  can 
be  pursued  without  a  cabinet,  and  yet  a  small  collection  of 
the  most  common  minerals  is  almost  indispensable,  and  can 
easily  be  obtained  for  comparison.  Fossils  are  more  diffi- 
cult to  secure.  The  teacher  must  rely  mainly  on  his  own 
collection  and  exchanges  with  friends.  Plaster  casts  of 
typical  genera  and  species  can  be  purchased  of  Prof.  Henry 
A.  Ward,  of  Rochester,  N.  Y.  They  answer  all  the  purposes 
of  instruction,  and  in  color  and  form  can  scarcely  be  dis- 
tinguished from  the  original  specimens.  Information  con- 
cerning the  cost  of  small  cabinets  can  be  obtained  of  the 
publishers  of  this  work.  Geological  excursions  to  river 
channels,  quarries,  ravines,  railroad  cuttings,  mines,  gravel 
beds,  stone  fences,  &c.,  furnish  most  valuable  information 
and  healthful  recreation.  A  steel  hammer  of  the  form 


10  SUGGESTIONS     TO     TEACHERS* 

shown  in  Fig.  i  will  be  found   most  generally  useful  ;  the 
edges  should  be  square,  the  socket 

FlG*  *'  large'  the  handle  strong>  and  the 

P^  entire  weight  about  two  pounds. 

,&d  ,;E^SfifiSSii^^^      Rock    specimens    should    not  be 

over  three  inches  square   and  an 

A   GEOLOGICAL   HAMMER.  •         1         i    •     i  11  ill  1 

inch  thick,  and  should  be  neatly 

trimmed.     The  locality  of  each  specimen  should  be  care- 
fully noted  and  preserved. 

The  diagram  at  the  commencement  of  each  general  sub- 
ject forms  an  analysis  of  the  topic.  The  author  is  accus- 
tomed to  have  this  placed  upon  the  blackboard,  and  to 
conduct  the  recitation  from  it,  without  asking  questions, 
excepting  as  occasion  may  suggest  the  necessity  of  addi- 
tional information,  or  a  closer  investigation  of  the  pupil's 
knowledge.  Questions  for  review  are  given  in  the  Appen- 
dix. It  is  suggested  that  teachers  instruct  their  pupils  to 
assign  such  fossils  as  they  may  find,  or  have  the  privilege  of 
examining,  first,  to  the  sub-kingdom  ;  second,  to  the  class ; 
and  third,  to  the  order,  but  not  to  the  family,  genus,  or 
species,  except  in  case  of  well-known  fossils.  Better  satis- 
faction will  be  given,  and  results  secured,  by  doing  so 
much  well,  than  by  a  vain  attempt  to  teach  everything  in  a 
brief  school-term. 

Never  let  a  pupil  recite  a  lesson,  nor  answer  a  question, 
except  it  be  a  mere  definition,  in  the  language  of  the  book. 
The  text  is  designed  to  interest  and  instruct  the  pupil ;  the 
recitation  should  afford  him  an  opportunity  of  expressing 
what  he  has  learned,  in  his  own  style  and  words. 


CONTENTS 


I.  PAGB 

INTRODUCTION, 17 


II. 
LITHOLOGICAL  GEOLOGY,       . 

III. 
HISTORICAL  GEOLOGY,  .    91 

IV. 
THE   AGE   OF   MAN, 241 


APPENDIX. 

QUESTIONS, 257 

GLOSSARY, .       .        .275 

INDEX, 277 


TN  a  valley,  centuries  ago, 

-*-  Grew  a  little  fern  leaf,  green  and  slender, 
Veining  delicate  and  fibres  tender, 

Waving  when  the  wind  crept  down  so  low  ; 
Rushes  tall,  and  moss,  and  grass  grew  round  it, 
Playful  sunbeams  darted  in  and  found  it, 
Drops  of  dew  stole  down  by  night  and  crowned  it. 

But  no  foot  of  man  e'er  came  that  way — 

Earth  was  young  and  keeping  holiday. 

Monster  fishes  swam  the  silent  main, 

Stately  forests  waved  their  giant  branches, 
Mountains  hurled  their  snowy  avalanches, 

Mammoth  creatures  stalked  across  the  plain  ; 
Nature  revelled  in  grand  mysteries  ; 
But  the  little  fern  was  not  of  these, 
Did  not  number  with  the  hills  and  trees, 

Only  grew  and  waved  its  sweet  wild  way  ; 

No  one  came  to  note  it  day  by  day. 

Earth,  one  time,  put  on  a  frolic  mood, 

Heaved  the  rocks  and  changed  the  mighty  motion 

Of  the  deep,  strong  currents  of  the  ocean  ; 
Moved  the  plain  and  shook  the  haughty  wood, 

Crushed  the  little  fern  in  soft,  moist  clay, 

Covered  it  and  hid  it  safe  away. 

Oh,  the  long,  long  centuries  since  that  day  ! 
Oh,  the  changes  !  Oh,  life's  bitter  cost ! 
Since  the  useless  little  fern  was  lost. 

Useless  ?    Lost  ?    There  came  a  thoughtful  man, 
Searching  Nature's  secrets,  far  and  deep  ; 
From  a  fissure  in  a  rocky  steep 

He  withdrew  a  stone  o'er  which  there  ran 
Fairy  pencillings,  a  quaint  design, 
Leafage,  veining,  fibres,  clear  and  fine, 
And  the  fern's  life  lay  in  every  line  ! 

So,  I  think,  God  hides  some  souls  away, 

Sweetly  to  surprise  us  the  Last  Day  ! 

MARY  BOLLES  BRANCH. 


"  3(n  t&e  beginning 
createn  rfje  fjeatien  anti  tfte  eartf)/ 


ANALYSIS    OF    INTRODUCTION. 


I.  ORIGIN  OF  THE  EARTH  ACCORDING  TO  THE  NEBU- 
LAR HYPOTHESIS. 

II.  SCENIC  DESCRIPTION. 
III.  DEFINITION  OF  GEOLOGY. 

i.  THE  SOLID  SHELL. 


IV.  THE     EARTH'S 
CRUST. 


V.  METHODS  OF 
GEOLOGIC 
STUDY. 


2.  PROOF  OF 

THE 

INTERNAL 
HEAT  OF 

THE 


1.  Temperature. 

2.  Artesian  Wells. 

3.  Hot  Springs. 

4.  Elevations  and  De- 

pressions. 

5 .  Volcanoes. 


EARTH.       6.  Earthquakes. 

1.  NATURE'S  LAWS  UNIVERSAL. 

2.  SEDIMENTARY  ROCKS. 

3.  TEACHINGS  OF  SED.  ROCKS. 

4.  IGNEOUS  ROCKS. 

5.  TEACHINGS  OF  IG.  ROCKS. 

6.  FOSSILS. 

7.  TEACHINGS  OF  FOSSILS. 

8.  GLACIERS. 

9.  TEACHINGS  OF  GLACIERS. 

a.  Caves. 


10.  CHKONOLOGY. 


b.  Lake-bottoms. 

c.  Scottish    Illus- 

trations. 

d.  Italian     Illus- 

tration, 


INTRODUCTION. 

27ie  Origin  of  the  IZarlh's  Crust  according 
to  the  Nebular  Hypothesis.*— Our  earth  was  once, 
doubtless,  a  glowing  star.  In  that  far  off  beginning  it 
shone  as  brilliantly  as  do  now  the  sun  and  the  fixed 
stars.  In  process  of  time  it  cooled  from  a  gaseous  to  a 
liquid  form.  It  then  assumed  a  spherical  figure  in 
obedience  to  the  same  familiar  laws  of  force  which 
round  a  drop  of  dew.  Its  atmosphere  comprised  not 
only  the  gases  that  compose  our  present  atmosphere, 
but  all  the  oxygen  and  carbon  now  locked  in  the  rock 
and  coal  masses  of  the  earth,  vast  quantities  of  min- 
eral matter  vaporized  by  the  fierce  heat,  and.  in  the  form 
of  superheated  steam,  all  the  water  which  now  fills  the 
ocean.  The  air,  thus  dense  with  moisture  and  metallic 
vapors,  rested  on  an  ocean  of  fire.  Ages  passed,  and 
the  earth,  cooling  as  its  heat  became  changed  to  other 
forms  of  force,  began  to  show  on  its  surface  patches 
of  solid  substance,  like  the  floating  films  that  first  appear 

*  See  Fourteen  Weeks  in  Astronomy,  p.  282.    THE  NEBULAR  HYPOTHESIS. 


18  GEOLOGY. 

on  water  as  it  passes  into  ice.  These,  gradually  combin- 
ing, formed  at  last  a  thin  crust  over  the  entire  exterior. 
This  was,  however,  constantly  rent  asunder  by  eruptions 
from  the  molten  mass  beneath.  Huge  crevices  were 
opened,  and  torrents  of  liquid  lava,  ejected  from  the 
cracks  and  seams,  were  poured  in  fiery  floods  over  the 
scarcely  solid  crust.  The  surface,  arid  and  burning, 
bristled  with  ragged  eminences,  or  was  furrowed  with 
enormous  clefts  and  cracks.  But  the  earth  had  ceased 
to  shine  as  a  star,  and  henceforth  was  itself  to  be 
lighted  and  at  last  heated  from  other  bodies.  As  the 
globe  continued  to  cool,  a  time  arrived  when  the  heat 
was  not  sufficient  to  support  the  water  in  the  form  of 
vapor.  Under  the  tremendous  pressure  of  the  dense 
atmosphere,  the  steam  was  precipitated,  boiling  hot, 
upon  the  heated  earth  below.  Reva£orized,  it  ascended 
again  only  to  be  condensed  and  returned  as  rain.  This 
process,  long  continued,  cooledjthe  garth  yet  more  rap- 
idly. The  crust,  shrinking  and  cracking  as  it  hard- 
ened, became  still  more  uneven  with  wrinkles  and  folds, 
yawning  gulfs  and  fissures.  The  hot  rain  falling  on 
the  volcanic  peaks,  the  torrents  which  poured  down  the 
mountain  sides  and  through  the  valleys,  all  combined 
to  dissolve  the  rock  and  sweep  the  sediment  into  the 
deeper  hollows.  The  crust  had  not  yet  attained  the 
consistency  necessary  to  resist  the  pressure  of  the  heated 
gases  and  liquids.  Hence,  in  this  manner  also,  enor- 
mous dislocations  were  made,  whose  folds  and  uplifts 
with  deep  gulfs  and  belching  lavas  denoted  terrific 
convulsions.  Thus  a  fierce  conflict  was  raging  between 
fire  and  water.  At  last  the  water  triumphed,  and  the 
ocean  became  universal.  A  hot,  muddy,  shallow  sea 


INTRODUCTION.  19 

surged  round  the  earth  from  pole  to  pole.  The  internal 
heat  of  the  earth  made  the  temperature  uniform  over 
the  entire  surface,  and  hence  there  were  no  great  oceanic 
or  aerial  currents. 

Astronomy  teaches  us  the  probable  origin  of  our  globe. 
As  soon  as  the  crust  began  to  be  formed  by  the  mingled 
action  of  lire  and  water,  Geology  steps  in  to  explain  the 
phenomena.  In  this  vague  and  nebulous  border-land  the 
two  sciences  meet.  From  that  time  we  find  that  the 
earth  entered  on  a  regular  series  of  progressive  revolu- 
tions which  gradually  fitted  it  for  the  introduction  of  life. 

The  Mosaic  Account  of  the  Creationi^iwim  l) 
us  that  "  the  earth  was  at  first  without  form  and  void ; 
and  darkness  was  upon  the  face  of  the  deep."  "With  the 
first  motion  of  nebulous  matter  light  was  developed,  or, 
in  the  nervous  language  of  Scripture— "  God  said,  Let 
there  be  light."  Thus  ended  the  work  of  the  first  day.* 


*  The  word  "day"  is  of  course  considered  not  as  a  literal  day,  but  as  sym- 
bolical of  a  long  period  of  time — ages,  during  which  God  was  fitting  this  earth 
as  a  home  for  man.  The  idea  of  exact  days  of  twenty-four  hoars  each  is  neither 
required  by  the  original  nor  by  the  scope  of  the  narration.  The  word  "day" 
itself  is  used  in  four  senses  in  the  description.  The  Christian  fathers  did  not 
interpret  it  as  a  common  day.  Augustine,  in  the  fourth  century,  called  the 
days  of  creation  "  ineffable  days,"  and  described  them  as  "  alternate  births  and 
pauses  in  the  work  of  the  Almighty— the  boundaries  of  periods  in  the  vast 
evolution  of  the  worlds."  How  glorious  the  idea  which  we  here  obtain  of 
God,  as,  through  measureless  ages  in  which  he  is  rich,  resting  not,  hasting 
not,  but  slowly  and  by  the  steady  operation  of  His  own  laws,  He  works  out 
to  the  finest  detail  His  mighty  thought  of  a  world.  Moses  gives  but  the  grand 
outline  of  this  creative  act,  an  outline  which  Geology  is  filling  up  rapidly  and 
surely.  The  Mosaic  account  is  a  hymn,  full  of  poetry  and  grandeur,  n^t  a 
rlose.  Ryflct1  ^ciftntiflfj  rftr.nrfl  of  events.  Yet  its  truths  were  inspired  by  the 
same  God  who  made  the  world.  As  such  we  receive  the  records  of  both  rev- 
elation and  nature,  and  gladly  notice  their  harmony  in  all  their  grand  teachings. 
As  yet  Geology  is  in  its  infancy,  and  we  are  often  able  only  to  suggest  and 
intimate  what  may  hereafter  be,  firmly  believing  that  God's  truth  must  stand, 
whether  it  be  revealed  in  the  rock  or  in  the  book. 


W  GEOLOGY. 

On  the  second,  the  firmament  or  atmosphere  was  formed, 
separating  the  clouds  above  from  the  sea  below,  which, 
as  the  revelations  of  both  the  rock  and  the  book  teach 
us,  as  yet  covered  the  entire  earth.  This  was  the  work 
of  the  second  day,  that  long  era  of  cooling  and  consolida- 
tion that  separated  the  formless  period  of  chaos  from  the 
birth  of  the  continents. 

Scenic  Description. — Let  us  imagine  the  scen- 
ery of  that  primitive  period.  A  dense  atmosphere  of 
steam,  metallic  vapors,  and  sulphurous  clouds  which 
conceals  the  sun,  and  through  which  the  light  of  moon  or 
star  never  penetrates ;  an  ocean  of  boiling  water,  heated 
at  a  thousand  points  from  the  central  fire ;  low,  half- 
molten  islands,  dim  through  the  fog,  and  scarcely  more 
fixed  than  the  waves  themselves  that  heave  and  tremble, 
lashed  into  fury  by  perpetual  tempests ;  roaring  geysers, 
that  ever  and  anon  throw  up  intermittent  jets  of  boil- 
ing water  and  steam  from  these  tremulous  lands.  In 
the  dim  horizon  the  red  gleam  of  fire  shoots  forth  from 
yawning  chasms,  and  fragments  of  molten  rock  with 
clouds  of  ashes  are  borne  aloft;  incessant  flashes  of  light- 
ning evoked  by  the  vast  chemical  changes  which  are 
taking  place,  dart  to  and  fro,  shedding  a  lurid  glare 
upon  the  seething  ocean-cauldron  beneath ;  while  bursts 
of  echoing  thunder,  peal  on  peal,  complete  the  grand  but 
awful  picture. 

Geology  (ge  the  earth,  and  logos  a  discourse)  may  be 
defined  as  the  history  of  the  earth's  crust  as  taught  by  its 
rocks  and  fossils. 


INTRODUCTION.  21 

2 he  JZarth's  Crust. — This  is  evidently  thickening 
from  age  to  age  as  the  cooling  process  goes  on.  Our 
examination  of  it  is  very  superficial,  extending  down- 
ward not  more  than  ten  miles.  On  a  terrestrial  globe, 
eighteen  inches  in  diameter,  the  deepest  wells,  mines, 
and  valleys  would  be  exaggerated  by  a  delicate  scratch 
upon  the  varnish  with  a  pin.  It  is  generally  believed, 
however,  that  the  solid  shell  is  not  over  fiffrjr  miles  in  x 
thickness,  and  that  the  interior  is  still  a  molten  mass. 
The  facts  upon  which  this  opinion  rests  are  as  follows : 

(1.)  THE  TEMPERATURE  INCREASES  AS  WE  DESCEND. 
—The  rate  varies  in  different  localities,  but  is  always 
over  1°  F.  for  every  hundred  feet.  At  fifty  miles  this 
would  give  a  temperature  of  at  least  3000°  F.,  sufficient 
to  melt  the  most  refractory  rocks.*  At  a  depth  of  fifty 
or  sixty  feet,  there  is  a  uniform  temperature,  unaffected 
by  the  vicissitudes  of  the  seasons ;  and  in  deep  mines  the 
heat  becomes  almost  unendurable. 

(2.)  ARTESIAN  WELLS  FURNISH  WARM  WATER. — The 
hospital  at  Grenelle  is  heated  by  water  from  an  Artesian 

*  It  should  here  be  noticed  that  the  current  of  geologic  thought  now  sets 
toward  the  view  that  the  interior  of  the  earth  is  solid.  Among  other  objections 
urged  against  its  being  a  fluid,  as  has  been  heretofore  universally  held,  are  the 
following :  1.  That  the  attraction  of  the  sun  and  the  moon  upon  such  a  liquid 
ocean  would  raise  a  tidal  wave  that  would  produce  regular  and  sensible  undula- 
tions of  the  crust ;  and  that  to  make  the  earth  as  inflexible  as  it  is,  would  require 
it  to  be  solid  halfway  to  the  centre.  2.  That,  as  pressure  elevates  the  melting- 
point  of  a  substance,  the  immense  weight  of  the  earth's  crust  would  keep  the 
interior  solid,  even  at  the  high  temperature  supposed  there  to  exist.  By  those 
holding  this  view,  the  word  "•  crust "  is  used  to  indicate  the  rocks  of  the  earth  as 
far  dowr?  as  they  have  been  examined.  Volcanoes  are  accounted  for  on  this 
theory  by  supposing  that  there  are  isolated  caverns  full  of  molten  matter,  or  that 
the  rocks  are  locally  melted  here  and  there  by  the  enormous  friction  caused  by 
their  shifting  and  rubbing  together  during  the  contraction  of  the  surface  in  its 
constant  cooling.  The  expulsion  of  the  liquid  mass  is  thought  to  be  due  to  the 
explosive  violence  of  steam  produced  when  water  by  any  chance  percolates  down 
to  the  heated  mass.— The  average  specific  gravity  of  rocks  is  2.5,  while  that  ol  ^ 
the  earth  is  about  6£.  Hence  it  may  be  that  the  core  consists  of  metals,  as  iron, 
which  would  account  for  the  earth's  magnetism.  (See  Physics,  p.  190.) 


2  GEOLOGY. 

well  1800  feet  deep.  In  Wurtemburg,  large  manufac- 
tories are  warmed  in  the  same  manner,  the  water  being 
conducted  through  the  buildings  in  metallic  pipes.  In 
the  Garden  of  Plants,  in  Paris,  the  pipes  are  laid  in  the 
soil ;  and  at  Erfurt,  Saxony,  a  salad  garden  is  thus  made 
to  yield  its  proprietor  an  income  of  $60,000  per  annum. 
The  well  at  Louisville,  Ky.,  furnishes  water  of  a  steady 
temperature  of  76^°,  and  the  one  at  Charleston,  1250 
feet  deep,  water  of  87°. 

(3.)  HOT  SPRINGS  AND  GEYSERS.— One  of  the  former 
in  Arkansas  has  a  temperature  of  180°.  The  geysers  of 
Iceland  and  California  are  fountains  of  boiling  water, 
The  great  geyser  throws  a  column  of  mingled  steam  and 
water,  eight  yards  in  diameter,  to  a  height  of  200  feet» 
Near  the  Sahwatch  River,  Col.,  is  an  immense  spring  so 
hot  that  the  hunters  sometimes  cook  their  provisions 
in  it. 

(4.)  ELEVATIONS  AND  DEPRESSIONS  OF  THE  EARTH'S 
CRUST. — The  land  in  various  places  has  been  uplifted  or 
depressed,  either  by  convulsive  throes  or  by  a  slow  move- 
ment continued  through  centuries.  This  indicates  that 
the  ground  on  which  we  tread  has  not  an  unyielding 
support.  (See  note,  p.  253.) 

(5.)  VOLCANOES. — These  throw  up  great  masses  of  lava, 
which  is  merely  molten  rock.  There  are  several  hundred 
volcanoes  which  are  known  to  be  either  constantly  or  oc- 
casionally active.  The  amount  of  melted  matter  they  eject 
is  enormous.  Two  streams  of  lava  flowed  from  Skaptar 
Jokul,  a  crater  in  Iceland,  in  1783 — one  fifty  miles  long 
and  twelve  broad,  the  other  forty  miles  long  and  seven 
broad;  each  was  one  hundred  feet  deep.  When  we  think 
of  such  fiery  torrents,  and  that  the  lava  everywhere  is 


INTRODUCTION.  %8 

essentially  the  same  in  its  composition,  we  can  but  con- 
sider the  interior  of  the  earth  as  a  melted  mass,  and  the 
volcanoes  as  the  chimneys  of  this  huge  central  furnace. 

(6.)  EARTHQUAKES. — Within  the  past  fifty  years,  over 
2,000  earthquake  shocks  have  been  recorded.  They  are 
accompanied  by  volcanic  eruptions,  jets  of  boiling  water, 
and  heated  gases.  The  only  rational  explanation  is  that 
they  are  produced  by  tidal  waves  or  some  terrific  convul- 
sion in  the  fiery  ocean  beneath. 

Methods  of  Geological  Study. — UNIFORMITY  or 
NATURE. — The  earth  is  a  microcosm — the  universe  in 
miniature.  The  laws  which  govern  our  world  govern 
all  worlds.  The  elements  of  matter  of  which  it  is  com- 
posed are  the  same  as  those  which  make  up  the  farthest 
star  in  space.  The  earth,  therefore,  as  Prof.  Dana  beau- 
tifully says,  though  but  an  atom  in  immensity,  is  immen- 
sity itself  in  its  revelations  of  truth  ;  and  science,  though 
gathered  from  our  small  sphere,  is  the  deciphered  science 
of  all  spheres.  As  this  world  thus  reveals  to  us  the 
laws  of  other  worlds,  so  the  present  time  makes  known 
to  us  the  laws  of  past  time.  The  geologist  believes 
in  the  unchangeableness  of  God's  laws.  All  results  are 
brought  about  by  established  methods.  The  same  effects 
are  always  produced  by  the  same  causes.  The  motions 
of  the  heavenly  bodies,  the  principles  of  heat,  electricity, 
chemical  affinity,  etc.,  are  the  same  now  as  they  have 
been  from  the  beginning.  The  geologist  sees  God  work- 
ing in  nature  through  the  uncounted  ages  of  the  past  as 
He  works  to-day,  not  fitfully,  but  uniformly  developing 
the  mighty  plan  of  the  universe.  Thus  a  knowledge  of 
the  present  is  the  magic  key  whereby  the  geologist  un- 


84  GEOLOGY. 

locks  the  history  of  the  past.     Let  us  notice  a  few  of  the 
practical  applications  of  this  principle. 

Sedimentary  ffioc&s. — The  rain  which  falls  on 
the  hills  runs  down  every  slope,  washing  the  soil  into 
the  brooks  and  rivers,  thence  to  the  lake  or  sea.  It  is 
there  deposited  as  a  soft  mud  or  sediment  in  horizon- 
tal layers  or  strata  (singular,  stratum).  The  process  is 
necessarily  slow,  but  uninterrupted.  Year  after  year, 
century  after  century,  adds  layer  on  layer,  the  more 
recent  deposits  concealing  the  more  ancient.  If  we 

FIG.  2. 


Ripple  Marks. 

visit  the  sea-shore,  we  shall  see  the  fine  sand  washed  up 
by  the  waves,  and  spread,  layer  upon  layer,  in  a  similar 
manner,  each  wave  rippling  its  tiny  ridges,  and  covering 
others  beneath  its  shifting  sands.  The  geologist  exam- 
ines the  solid  rocks,  and  finds  strata  composed  of  fine 
sediment  arranged  in  layers,  with  oftentimes  ripple  marks 
curving  the  surface,  appearing  as  distinct  as  if  the  tide 
had  just  ebbed.  He  finds  rocks  presenting  the  look  of 


INTRODUCTION.        •  25 

half-dried  mud  from  which  the  water  had  been  evapo- 
rated but  yesterday,  leaving  cracks  and  even  prints  of 

rain-drops  so  clearly  defined  that  one  can  tell  from  what 
j~  j 

direction  the  storm  came  which  fell  on  those  mud  flats 
of  the  olden  time.     (See  Fig.  3.)     He  notices  other  strata 

FIG.  3. 


a.  Modern  impressions  of  rain-drops. 

b.  Carboniferous  impressions  of  rain-drops. 

composed  of  sand,  gravel,  or  round  water-worn  pebbles, 
such  as  are  now  seen  along  the  shore  of  river  or  lake 
among  swiftly  moving  waters.  Again,  he  discovers  banks 
of  sand  or  clay  where  the  process  of  rock-making  is  still 
progressing,  and  the  material  is  in  all  stages  of  harden- 
ing. He  therefore  decides  that  all  similar  stratified  rocks 
have  been  formed  by  the  action  of  water,  and  hence  calls 
them  sedimentary. 

TEACHINGS  OF  THE  SEDIMENTARY  EOCKS. — The  water 
records  the  history  of  the  land.  Not  only  is  the  inani- 
mate dust  of  earth  carried  into  the  vast  storehouse  of 
the  sea,  but  there  lie  millions  of  shells  of  every  shape 


26  9  GEOLOGY. 

and  hue  ;  there,  into  the  soft,  oozy  bottom  settle  the 
remains  of  countless  fishes  which  have  thronged  the 
waters  ;  thither  float  leaves  and  reeds,  and  trees  torn 
up  by  the  tempest,  swept  seaward  from  every  shore  ; 
there  sink  skeletons  of  sea-fowls,  exhausted  land-birds, 
and  animals  borne  to  the  sea  by  rapid  rivers  ;  ships  with 
their  unclaimed  cargoes,  gone  on  their  final  voyage  and 
in  harbor  at  last  ;  drowned  mariners  lying  in  their  quiet 
graves  unconscious  of  the  fiercest  storm  that  sweeps 
above  them  —  all  these  varied  relics  are  slowly  buried  by 
the  ever-settling  sediment.  The  bottom  of  the  ocean  is 
a  cemetery  in  which  lie  the  dead  from  the  three  king- 
doms of  Nature.  Layer  by  layer  are  gathered  the  re- 
mains of  each  passing  year,  the  history  of  every  age 
being  thus  deposited  and  built  into  the  very  founda- 
tions of  the  earth.  Could  we  gain  access  to  this  sea- 
bottom,  we  should  find  revealed,  with  each  layer  turned 
up  by  our  spade,  a  fresh  page  of  the  history  of  the  world. 
The  ocean  is  now  making  up  a  continuation  of  this  his- 
tory. The  geologist  is  reading  the  earlier  volumes  in  the 
stratified  rocks,  the  sea-bottom  of  the  olden  time. 


ffioc&s.  —  The  geologist  watches  the  action 
of  volcanoes  and  earthquakes  at  the  present  day.  He 
notices  that  rocks  of  various  consistency  and  character 
are  formed  from  the  cooling  lava,  and  that  stratified  or 
sedimentary  rocks  are  displaced  and  rent,  the  fissures 
being  filled  with  injected  matter.  In  the  earth's  crust, 
at  various  places,  the  exact  counterparts  of  these  rocks 
and  these  displacements  occur.  The  rocks  are  not  ar- 
ranged in  layers,  but  piled  up  in  mountain  masses,  break- 
ing through  the  stratified  rocks,  tilting  and  throwing 


INTRODUCTION.  #7 

them  out  of  their  original  positions.  The  observer  has 
no  more  difficulty  in  accepting  the  evidence  that  the 
unstratified  rocks  give  of  former  igneous  action  and  con- 
vulsion than  in  admitting  the  eruptions  and  earthquakes 
of  Etna  and  Vesuvius. 

TEACHINGS  OF  THE  IGNEOUS  KOCKS.— The  geologist 
calls  all  rocks  which  indicate  the  action  of  fire  igneous, 
and  ascribes  dislocations  of  strata  and  filling  up  of  cracks 
with  igneous  products  to  the  operation  of  ancient  vol- 
canoes and  earthquakes.  If  he  is  not  correct  in  his  con- 
clusions, then  Nature  is  not  uniform,  and  is  making  the 
same  kind  of  rock  on  one  day.  by  fire  and  on  another  by 
water,  and  thus  all  the  history  of  the  past  is  a  delusion. 

Fossils  (fossilis,  dug  up)  is  a  name  applied  to  all 
animal  or  vegetable  remains  which  are  found  embedded 
in  the  rocks  of  the  earth's  crust.  What  we  have  already 
said  concerning  the  sedimentary  rocks  shows  us  how 
fossils  are  now  forming  and  have  been  formed  in  all 
time.*  As  the  autumnal  leaf  drops  into  the  stream,  and 


*  These  remains  were  known  to  the  ancients,  and  considered  "freaks  of  Na- 
ture." Tradition,  which  attributed  to  Achilles  and  other  heroes  of  the  Trojan 
war  a  height  of  twenty  feet,  is  traceable,  no  doubt,  to  the  discovery  of  ele- 
phants' bones  near  their  tombs.  Thus,  for  example,  we  are  assured  that,  in 
the  time  of  Pericles,  in  the  tomb  of  Ajax  was  found  a  knee-bone  of  that  hero 
which  was  as  la"rge  as  a  dinner  plate.  It  was,  probably,  the  fossil  knee-bone 
of  an  elephant.  The  Spartans  prostrated  themselves  before  the  remains  of 
one  of  these  animals,  in  which  they  thought  they  recognized  the  skeleton  of 
Orestes.  Some  bones  of  a  mammoth  found  in  Sicily  were  considered  as 
having  belonged  to  Polyphemus.  Even  the  learned  of  a  later  day  were  not 
exempt  from  these  blunders.  Felix  Plater,  Professor  of  Anatomy  at  Basle,  in 
1517,  referred  the  bones  of  an  elephant  discovered  at  the  roots  of  a  tree  torn  up 
by  the  wind  near  Lucerne,  to  a  giant  at  least  nineteen  feet  high.  He  even 
restored  it  in  a  skdleh  which  was  long  preserved  in  the  college  at  Lucerne. 
In  England,  similar  bones  were  regarded  as  those  of  the  fallen  angels  1  When 
geology  first  began  to  be  studied,  people  generally  considered  the  deposition  of 
fossils  as  having  a  connection  with_Noah^-flo°4'  Cuvier  found  the  skeleton 


a  E  o  L  o  G  r. 

becomes  imbedded  in  its  mud— as  the  trees  of  the  forest 
are  borne  down  by  the  flooded  river  and  are  ultimately 
entangled  in  the  sediment  of  its  estuary— as  the  coral 
reef  and  shell-bed  are  gradually  increasing  and  growing 
steadily  into  limestone  before  our  eyes — as  the  skele- 
tons of  animals  are  drifted  by  the  tide  and  fall  to  the 
sea-bottom  or  sink  into  rivers  and  marshes,  and  are  thus 
preserved  from  rapid  decay — so  in  all  time  past  have 
similar  agencies  been  at  work ;  here  preserving  the  bro- 
ken twig  and  the  fallen  forest,  there  the  coral  reef  and 
the  shell-bed,  and  anon  the  remains  of  animals  that  were 
borne  by  rivers  from  the  land,  or  drifted  by  the  waves  on 
the  muddy  sea-shore. 

TEACHINGS  OF  THE  FOSSILS. — Digging  in  the  soil,  we 
find  a  bone.  We  examine  it.  It  is  one  of  the  vertebrae 
of  a  horse.  We  believe  it  to  be  real.  It  is  not  a  "freak 
of  Nature,"  but  was  once  part  of  a  living  horse.  We  dis- 
cover some  strange  fossil  bone,  and  are  led  irresistibly  to 
a  similar  conclusion.  The  skilful  anatomist,  understand- 
ing perfectly  the  relation  that  exists  between  the  different 
parts  of  the  animal  frame,  whereby  each  portion  subserves 
its  part  toward  the  development  of  life  and  its  functions, 
can  restore  the  entire  form,  and  even  indicate  the  habits 
of  the  creatures  that  formerly  peopled  our  globe.  For 
example,  a  sharp  claw  belongs  to  a  flesh-eating  animal 
with  sharp  cutting  molars ;  a  hoof,  to  a  grazing  species 

of  a  gigantic  salamander  preserved  as  a  specimen  of  the  accursed  race  swal- 
lowed up  by  the  deluge. 

When  we  speak  of  fossils  being  converted  to  stone,  we  do  not  mean  that  the 
particles  of  the  original  substance  have  been  changed  to  stone,  but  that,  as  they 
decayed,  they  have  been  replaced  by  stone.  This  is  true,  however,  only  of  the 
fossils  of  the  older  formations.  The  new  ones  retain  their  original  substance. 
Shells  of  the  Tertiary  Period  can  often  scarcely  be  distinguished  from  modern 
onea,  while  sharks'  teeth  exhibit  their  enamel  intact. 


INTRODUCTION.  29 

with  broad  molars.  Knowing,  too,  the  conditions  neces- 
sary to  the  life  of  such  animals,  he  can  also  decide  upon 
the  climate,  food,  etc.,  which  then  existed.  Agassiz,  from 
a  single  scale,  reconstructed  an  entire  fish.  Subsequent 
discoveries  proved  his  idea  to  be  singularly  accurate.  The 
restoration  of  the  megalosaur  by  Hawkins  is  a  remarkable 
instance  of  a  similar  character.  (See  Fig.  83.)  A  /££ 

We  visit  the  sea-shore,  and  gather  shells  along  the 
beach.  On  digging,  we  discover  others  buried  from 
sight.  These  are  filled  with  damp  sand,  which  perfectly 
retains  their  impress.  In  the  quarry  among  the  layers 
of  sedimentary  rocks,  we  find  similar  fossil  shells.  They 
are  certainly  the  remains  of  ancient  life,  and  must  have 
existed  when  the  rock  was  in  process  of  formation.  They 
prove  the  rock  to  have  once  been  under  water.  If  the 
shells  are  marine,  it  was  the  sea ;  if  fresh  water,  a  lake  or 
river ;  if  intermediate,  an  estuary.  The  testimony  is  as 
conclusive  as  if  we  had  lived  by  that  ancient  shore,  and 
had  witnessed  their  growth,  decay,  and  entombment  in 
the  sand. 

In  certain  clay  beds  of  England,  shells  are  found  of 
species  now  existing  only  in  polar  seas.  We  thence  infer 
that  when  that  clay  was  deposited,  and  those  shells  were 
inhabited,  a  climate  similar  to  that  of  Greenland  must 
have  prevailed  in  British  latitudes.  Eemains  of  the  rein- 
deer and  musk  ox  occur  in  France.  These  indicate  a 
former  Arctic  temperature,  unless  we  are  to  suppose  that 
the  habits  of  those  animals  have  entirely  changed  since 
the  time  of  their  existence  in  southern  Europe. 

Action  of  Glaciers  (Gla'-seers). —  Philosophers 
have  carefully  studied  the  effects  of  moving  masses  of 


80  GEOLOGY. 

ice.  They  have  seen  how  the  glacier  pushes  its  way 
down  the  Alpine  valley,  grinding,  rounding,  smoothing, 
and  marking  the  rocks  over  which  it  passes,  and  de- 
positing at  the  bottom  its  burden  of  debris.  They  have 
watched  the  glaciers  of  polar  regions  collecting  on  the 
sea-shore  until  at  last  great  mountains  of  ice  break 
loose  and  float  southward.  They  have  seen  these  ice- 
bergs grounding  and  melting  in  a  more  genial  clime, 
where  they  finally  drop  their  load  of  rocky  fragments  on 
the  sea-bottom. 

TEACHINGS  OF  THE  GLACIERS. — The  geologist,  in  re- 
gions now  far  removed  from  glacial  action,  finds  the 
lower  extremities  of  mountain  glens  and  valleys  heaped 
with  mounds  of  sand  and  gravel,  and  the  rocky  surface 
marked  with  parallel  grooves,  such  as  no  known  agency 
except  the  glacier  ever  produces.  Resting  on  the  lower 
hills  and  scattered  over  valley  and  plain  beyond,  he  sees 
great  bowlders  of  a  weight  far  exceeding  the  transporting 
power  of  water,  miles  removed  from  their  parent  rocks, 
and  with  their  sides  smoothed  and  marked.  He  ascribes 
these  results  to  glaciers  and  icebergs.  He  assumes  that 
these  mountains  were  once  covered  with  snow,  these 
glens  once  filled  with  glaciers,  and  that  these  lower 
lands  were  the  bottoms  of  seas  on  which  floating  ice- 
bergs grounded,  and,  melting,  left  their  loads  of  rocky 
debris. 

Chronology. — Many  geological  facts  aid  in  deter- 
mining the  relation  of  different  events  in  respect  to  time. 
The  following  instances  illustrate  the  method : 

CAVES.  —  In  certain  caves  the  bones  of  various  ani- 
mals are  found  embedded  in  a  calcareous  deposit,  which 


INTRODUCTION.  SI 

has  accumulated  on  the  floor  by  water  slowly  dripping 
from  the  roof.  Many  of  the  bones  have  been  gnawed,  and 
the  hollow  ones  split  lengthwise.  The  geologist  considers 
the  former  the  work  of  den-frequenting,  carnivorous 
animals,  and  the  latter  of  a  marrow-sucking  race  of 
men.  This  conclusion  is  still  further  substantiated  by 
finding  traces  of  the  hyena,  and  also  stone-hatchets, 
ashes,  and  charred  sticks  of  wood.  Man,  only,  lights  a 
fire.  Hence  we  are  as  sure  of  the  existence  of  a  rude 
cave-dwelling  tribe  of  men  as  if  we  had  witnessed  their 
grim  countenances  lighted  up  by  the  fires  of  which 
those  fragments  were  the  latest  embers.  The  hyena  and 
the  cave-dwellers  lived  at  the  same  epoch.  The  deeper 
the  layer  the  older  the  remains.  If  we  can  only  deter- 
mine the  rate  at  which  the  soil  accumulates,  we  can 
estimate  with  some  degree  of  accuracy  their  antiquity. 

LAKE-BOTTOMS. — We  drain  a  level,  basin-shaped  mead- 
ow. The  general  form  and  location  suggest  the  idea 
that  it  may  anciently  have  been  the  site  of  a  lake. 
The  moment,  however,  we  dig  below  the  surface,  the 
geologic  evidence  converts  the  inference  into  a  matter 
of  certainty.  We  pass  through  first  the  soil,  next  a  layer 
of  peat,  then  one  of  marl,  and  lastly,  one  of  clayey  sedi- 
ment. In  the  peat  we  find  antlers  of  deer  and  bones  of 
oxen ;  in  the  marl,  fresh- water  shells ;  and  in  the  sedi- 
ment, a  log  hollowed  out  into  a  rude  canoe.  Here  we 
have  the  whole  history  of  the  lake,  and  in  reading  it  we 
can  trace  the  successive  stages  as  clearly  as  if  we  had 
lived  by  its  shores  from  the  time  it  was  a  sheet  of  shal- 
low water  to  the  hour  of  its  final  obliteration.  First, 
the  open  lake,  over  which  the  simple  native  paddled  his 
rude  canoe ;  second,  the  shallower  sheet,  where  fresh- 


S2  GEOLOGY. 

water  shell-fish  luxuriated  in  myriads,  and  succeeded 
each  other,  generation  after  generation ;  third,  the  peat 
marsh,  over  which  deer  and  oxen  occasionally  ventured, 
and  were  mired ;  and  fourth,  the  level  meadow,  when 
the  site  became  too  dry  for  the  peat-forming  plants  to 
flourish.  We  have  no  exact  chronology  for  these  events, 
and  can  decide  only  their  order.  The  canoe  may  have 
sunk  one  thousand  or  five  thousand  years  ago,  for  aught 
we  know.  If,  however,  we  can  form  some  idea  of  the 
rate  at  which  the  sediment  was  deposited,  or  the  marl 
and  the  peat  formed,  we  can  then  judge  somewhat  of  its 
antiquity. 

SCOTTISH  ILLUSTRATIONS. — Such  ancient  lake-bottoms 
are  seen  in  the  Lowlands  of  Scotland.  The  geologist 
finds  below  the  peat-bog  the  bones  of  horse,  pig,  deer, 
dog,  and  man  ;  deeper  still,  the  Roman  eagle  or  sword ; 
next,  the  bones  of  the  wild  ox,  bear,  wolf,  beaver ;  then 
the  wooden  canoe ;  below  the  marl,  bones  and  antlers  of 
the  gigantic  Irish  elk,  and  tusks  of  the  great  mammoth  ; 
and  at  the  bottom  the  solid  rock,  strewn  with  ice-borne 
blocks,  the  original  bed  of  the  lake  when  its  waters  were 
first  gathered  together.  Occasionally,  also,  raised  mounds 
of  piles,  plank,  branches,  stones,  and  other  material  are 
laid  bare.  These  were  the  foundations  of  the  lake-dwell- 
ings of  former  days,  raised  by  primitive  men  for  their 
defence.  They  reveal  stone  hammers,  flint  spear-heads, 
split  bones,  and  fragments  of  rude  pottery-ware.  What 
a  marvelous  history  we  read  from  these  records  of  Na- 
ture !  In  the  beginning  there  is  the  clear  sheet  of 
water  rippling  in  the  European  landscape — for  Great 
Britain  has  not  yet  been  separated  from  the  continent 
— surrounded  by  forests  of  pine,  birch,  and  willow.  The 


INTRODUCTION.  33 

climate  is  severe,  and  the  woolly-haired  mammoth 
tramps  through  the  overhanging  bushes  down  to  the 
water's  edge.  Centuries  pass.  Reindeer  and  Irish  elk 
betake  themselves  to  the  water  in  summer,  and  sink  into 
its  miry  depths,  or  seek  to  cross  its  frozen  crust  during 
the  winter's  snow,  and  are  buried  beneath  the  treacher- 
ous surface.  Ages  roll  on.  The  climate  becomes  milder, 
and  Britain  is  detached  from  the  continent.  The  lake 
is  gradually  becoming  shallow ;  reeds  and  bulrushes  en- 
croach upon  its  margin ;  oak  clumps-  adorn  its  banks, 
along  which  prowl  the  wolf  and  bear ;  the  beaver  builds 
his  dam  across  the  entering  stream,  and  the  wild  ox  and 
red  deer  stand  lolling  in  its  cool  waters.  A  race  of  short, 
broad,  round-headed  men  settle  by  the  shore,  pile  the 
mounds  and  wattle  their  simple  lake-dwellings  ;  with  fire 
and  stone  adzes  scoop  out  the  oak-trunks  into  canoes, 
spear  the  ox  and  deer  in  the  woods,  and  enjoy  the  com- 
forts of  a  dawning  civilization.  Time  passes.  Still  the 
lake  grows  shallower,  and  its  reedy  margin  broader.  A 
new  race  of  men — taller,  higher-headed,  and  more  nimble 
— take  possession  of  the  scene.  They  settle  the  slopes, 
erect  their  rude  altars  in  the  oak  clumps,  domesticate  the 
ox,  horse,  and  dog,  and  attempt  a  scanty  cultivation  of 
the  soil.  The  Roman  legions  at  last — we  know  the  date 
of  that  event,  about  two  thousand  years  ago — invade  the 
country,  scatter  the  natives,  and  encamp  by  the  lake. 
They  erect  their  votive  altars,  make  plank  roads  through 
the  marshy  borders,  and  drop  their  implements  and  uten- 
sils by  the  side  of  those  of  the  ancient  Briton.  The  pre- 
historic ages  have  now  passed,  and  we  can  more  easily, 
but  still  somewhat  confusedly,  continue  the  onward  his- 
tory of  the  fast  lessening  waters.  The  Romans  dis- 


OE  OL  0  G  T. 


FIG.  30. 


appear.  Celt  and  Saxon  contend  for  the  soil,  and  we 
trace  in  the  uppermost  bog-earths  the  remains  of  existing 
breeds  of  oxen,  sheep,  horses,  pigs,  dogs,  and  other  animals, 
and  even  implements  of  iron  belonging  to  successive 
stages  of  civilization  down  to  the  present  time. — (Page^) 

Italian  Illustration. — Near  the  town  of  Pozzuoli, 
Italy,  are  the  remains  of  the  ancient  temple  of  Serapis. 

Three  marble  pillars, 
forty-two  feet  high, 
are  especially  notice- 
able. They  stand 
on  a  pavement  now 
three  feet  under  wa- 
ter. Six  feet  be- 
neath is  another 
pavement.  For  a 
height  of  twelve 
feet  the  surface  of 
the  pillars  is  smooth ; 
but  above  that  a  zone 
of  nine  feet  in  width 
is  perforated  with 
holes,  at  the  bottom 

Temple  of  Serapis,  Pozzuoli.  of  each  Qf  which  lies 

the  shell  of  a  little  boring  bivalve  still  found  in  the  neigh- 
boring waters.  These  facts  show  that  the  ancient  pave- 
ment must  have  settled  six  feet,  when  the  second  one  was 
constructed.  Later,  it  subsided  twenty-one  feet  beneath 
the  water,  giving  the  borers  an  opportunity  to  penetrate 
the  stone.  Next,  the  pavement  rose,  lifting  the  bivalves 
out  of  the  water.  Previous  to  1845  the  foundation  was 
again  slowly  sinkino-.  but  since  has  been  steadily  rising. 


(A    Stone=(Discourse) 


o4.nct  this  our  life,  exempt  from  public  haunt. 
Finds  tongues  in  trees,   books  in  the  running  brook»9 
<S«rmons  in  stones,  and  good  in  everything." 

SHAKESPEARE. 


Geology  (lithos,  a  stone,  and  logos,  a 
discourse,)  means,  literally,  a  discourse  about  stones.*  It 
treats  of  (1)  the  Composition,  (2)  the  Classifica- 
tion, and  (3)  the  Structure  of  the  rocks  which  make 
up  the  earth's  crust.  Underneath  the  soil  and  the  sea 
there  is  everywhere  a  rocky  foundation  which  protects 
us  from  the  fiery  interior.  Along  the  sea-shore,  river- 
side, road-cuttings,  etc.,  this  solid  basement  is  exposed 
to  view.  It  is  generally  arranged  in  layers,  sometimes 
loosely,  as  sand,  clay,  or  gravel,  and  sometimes  partly 
hardened  into  stone.  Since  it  passes  thus  insensibly 


*  TherJ  is  no  natural  object  out  of  which  more  can  be  learned  than  out  of 
stones.  They  seem  to  have  been  created  especially  to  reward  a  patient  ob- 
server. Nearly  all  other  objects  in  Nature  can  be  seen,  to  some  extent,  with- 
out patience,  and  are  pleasant  even  in  being  half  seen.  Trees,  clouds,  and 
rivers  are  enjoyable  even  by  the  careless.  But  the  stone  under  the  foot  has 
nothing  for  carelessness  but  stumbling  ;  no  pleasure  is  to  be  had  out  of  it,  nor 
food,  nor  good  of  any  kind ;  nothing  but  symbolism  of  the  hard  heart  and 
the  unfatherly  gift.  Yet  do  but  give  it  some  reverence  and  watchfulness,  and 
there  is  bread  of  thought  in  it  more  than  in  any  other  lowly  feature  of  all  the 
landscape.  For  a  stone,  when  it  is  examined,  will  be  found  a  mountain  in 
miniature.  The  fineness  of  Nature's  work  is  so  great  that  into  a  single  block, 
a  foot  or  two  in  diameter,  she  can  compress  as  many  changes  of  form  and  struc- 
ture, on  a  small  scale,  as  she  needs  for  her  mountains  on  a  large  one;  and 
taking  moss  for  forests,  and  grains  of  crystal  for  crags,  the  surface  of  a  stone, 
in  most  cases,  is  more  interesting  than  the  surface  of  a  hill ;  more  fantastic  in 
form  and  inconceivably  richer  in  color.— Ruskin. 


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40  LI  THO  LOGICAL      GEOLOGY. 

from  one  stage  of  consolidation  into  another,  the  geolo- 
gist applies  the  term  rock  alike  to  all.  The  desert  of 
Sahara  is  a  sand-rock.  Ice  is  a  rock  as  certainly  as  is 
limestone. 


1. 


COMPOSITION    OF    THE    MOCKS. 


Rocks  are  composed,  in  general,  of  three  common  sub- 
stances— Quartz,  Clay,  and  Z/imeslone.  Wherever 
you  stand  on  the  solid  ground,  in  any  country  of  the 
globe,  you  may  be  sure  that  the  rock  under  you  is  mainly 
some  form  or  compound  of  one  or  more  of  these  earth- 
builders.* 

(i.)     SILICA 

/.  Quartz  (silica,  silex)  is  the  oxide  of  silicon,  a 
rare  non-metallic  substance  known  only  to  the  chemist. 
Silica  is  the  most  abundant  of  all  the  minerals,  compris- 
ing one-half  of  the  earth's  crust.  It  is  so  hard  that  it 
strikes  fire  with  steel,  scratches  glass  like  a  diamond,  and 


*  Since  there  were  so  few  substances,  Nature  seems  to  have  set  herself 
about  making  these  three  as  interesting  and  beautiful  as  she  can.  The  clay, 
being  a  soft  and  changeable  substance,  she  doesn't  take  much  pains  about— she 
only  brings  the  color  into  it  when  it  takes  on  a  permanent  form  on  being  baked 
into  brick.  (Raskin's  statement  does  not  hold  good  in  America.  For  examples, 
the  clays  of  Southern  Virginia  and  North  Carolina  are  beautifully  mottled,  the 
cliffs  at  Gay  Head  present  brilliant  tints,  and  the  porcelain  clays  of  Western 
Kentucky  exhibit  fine  coloring.)  But  the  limestone  and  flint  she  paints  in  her 
own  way,  in  their  native  state ;  and  her  object  in  painting  them  seems  to  be 
much  the  same  as  in  her  painting  of  flowers— to  draw  us,  careless  and  idle 
human  creatures,  to  watch  her  a  little,  and  see  what  she  is  about,  that  being,  on 
the  whole,  good  for  us,  her  children.  To  lead  us  to  do  this  she  makes  picture- 
books  for  us  of  limestone  and  flint ;  and  tempts  us,  like  foolish  children,  as  we 
are,  to  read  her  books  by  the  pretty  colors  in  them.  The  pretty  colors  in  her 
limestone  books  form  those  variegated  marbles  which  all  mankind  have  taken 
pains  to  polish  and  build  with  from  the  beginning  of  time  ;  and  the  pretty 


COMPOSITION     Of    THE    HOCKS.  J^l 

cannot  be  cut  with  a  knife.  It  has  no  cleavage,*  and 
breaks  into  irregular  fragments  having  a  glassy  lustre. 
It  is  insoluble  in  any  acid  (except  hydrofluoric),  and 
melts  only  in  the  heat  of  the  compound  blow-pipe.  On 

FIG.  4. 


A  Cluster  of  Quartz  Crystals  from  Lake  Superior. 


colors  in  her  flint  books  form  agates,  jaspers,  carnelians,  etc.,  which  men 
have,  in  like  manner,  taken  delight  to  cut  and  polish  and  make  ornaments  of 
from  the  beginning  of  time ;  and  yet  so  much  of  babies  are  they,  and  so  fond  of 
looking  at  the  pictures  instead  of  reading  the  books,  that  I  question  whether, 
after  six  thousand  years  of  cutting  and  polishing,  there  are  more  than  two  or 
three  out  of  any  hundred  who  know,  or  care  to  know,  how  a  bit  of  agate  or 
marble  was  made  or  painted.— Ruskin. 

*  Cleavage  is  the  property  of  splitting  with  smooth  surfaces  in  certain  fixed 
directions.  Many  crystals  separate  very  easily  in  those  joinings  which  Nature 
has  made. 


J$  L1THOLOG 1 CAL      GEOLOGY. 

account  of  its  hardness,  which  resists  the  action  of  the 
elements,  it  comprises  a  large  part  of  ordinary  pebbles, 
sand,  and  much  even  of  the  soil.  It  is  found  in  crys- 
tals of  the  form  shown  in  the  figure.  When  pure,  like 
those  of  other  minerals,  they  are  generally  small,  and 
sometimes  occur  in  beautiful  clusters.  Crystals  of  great 
size,  though  of  inferior  clearness,  are  occasionally  seen. 
Dartmouth  College  cabinet  possesses  a  group  weighing 
147  pounds.  At  Milan  is  a  single  crystal  3J  feet  long  and 
5J  feet  in  circumference,  estimated  to  weigh  870  pounds. 

2.  Itock  Crystal  is  the  clear  crystalline  quartz. 
The  name  is  derived  from  the  Greek  word  krustallos, 
meaning  ice.  The  purest  specimens  are  often  cut  for 
jewelry,  and  sold  as  "  white  stone "  and  "  California 
diamonds."  They  are  also  used  for  spectacle  glasses. 
Anciently  they  were  cut  into  vases  and  cups,  some  of 
which  are  still  preserved  as  curiosities.  It  is  said  that 
Nero,  on  learning  of  the  insurrection  which  led  to  his 
fall,  dashed  into  pieces  two  crystal  vases,  one  valued  at 
$3000.  Pure  quartz  sand  is  used  in  large  quantities  for 
making  glass. 

Quartz,  when  colored  by  the  various  metallic  oxides, 
presents  a  bewildering  variety.  The  young  geologist, 
after  having  gathered  a  very  respectable  collection  of 
minerals,  has  often  been  surprised  to  learn  that  he  has 
hardly  passed  outside  of  this  legion  family. 

3 '.  3tose  or  *Pinfc  Quartz  is  rarely  found  as  crys- 
tals, but  generally  as  a  massive  rock.  On  exposure  to 
the  light,  the  color  sometimes  fades,  but  it  can  be  re- 
stored by  leaving  the  stone  for  a  time  in  a  damp  place. 


COMPOSITION     OF     THE     ROCKS.  43 

SMOKY  QUARTZ  has  a  dark-brown,  smoky  tint.  It  is 
often  black  and  opaque,  except  in  thin  portions,  which 
are  semi-transparent. 

MILKY  QUARTZ  is  a  milk-white,  opaque,  massive 
variety,  looking  not  unlike  porcelain. 

GRANULAR  QUARTZ  consists  of  small  grains  of  quartz 
cemented  into  a  massive  rock.  It  has  a  texture  similar 
to  that  of  loaf-sugar,  and  oftentimes  crumbles  easily  into 
sand.  It  is  used  for  hearthstones,  furnaces,  etc.,  and, 
when  powdered,  for  making  sand-paper,  glass,  or  pottery. 

& .  jlmet/iyst  has  a  beautiful  purplish  tint  from  the 
oxide  of  manganese,  which  it  contains.  The  name  means 
"  a  preservative  from  intoxication,"  and  was  given  it  from 
a  belief  of  the  ancient  Persians,  that  wine  drunk  from  an 
amethyst  cup  lost  its  inebriating  properties. 

5 '.  Chalcedony  is  distinguished  by  its  waxy,  horn- 
like lustre.  It  has  generally  a  white  or  brownish  shade. 
When  bright  red,  it  is  a  carnelian.  When  brownish  red, 
a  sard.  When  colored  apple-green  with  nickel,  a  chrys- 
oprase. 

6 '.  Agate  is  a  kind  of  chalcedony,  in  which  the  dif- 
ferent shades  of  color  are  arranged  in  parallel  lines — the 
edges  of  the  layers  which  compose  the  stone.  These 
layers  are  very  like  the  coats  of  an  onion,  and  represent 
the  successive  deposits  by  which  the  agate  was  formed. 
They  are  often  so  thin  as  to  number  fifty  within  an  inch. 
When  the  lines  are  zigzag,  it  is  termed  a  fortification 
agate,  from  the  resemblance  to  the  irregular  outlines  of  a 
fortress.  When  the  stripes  alternate,  an  opaque  with  a 


44  LITHOLOGICAL      GEOLOGY. 

transparent  band,  the  stone  is  termed  an  onyx  (onyx,  a 
nail),  from  a  fancied  resemblance  to  the  alternating  lines 
on  the  finger-nail.  When  a  deep  brownish-red  stripe  (a 
sard)  alternates  with  a  white  one,  the  agate  is  called  a 
sardonyx.  When  a  yellowish-brown  oxide  of  iron  is  dis- 
seminated through  the  stone  in  moss-like  forms,  it  is 
termed  a  moss  agate. 

Keal  cameos  are  cut  from  the  onyx.  The  most  cele- 
brated of  the  ancient  cameos  is  the  Mantuan  vase  at 
Brunswick.  It  was  cut  from  a  single  stone.  It  is  in  the 
form  of  a  cream-pot,  about  7  inches  high  and  24-  broad. 
On  its  outside,  which  is  of  a  brown  color,  there  are  white 
and  yellow  groups  of  raised  figures,  representing  Ceres 
and  Triptolemus  in  search  of  Proserpine.  The  lines  of 
agates  sometimes  present  a  striking  resemblance  to  vari- 
ous objects.  Some  are  so  remarkable  as  to  be,  without 
doubt,  exceedingly  ingenious  works  of  art.  Thus,  Pliny 
tells  of  an  agate,  belonging  to  Pyrrhus,  in  which  were 
pictured  the  nine  muses,  and  Apollo  in  the  midst  playing 
on  his  lyre.  Agates  are  very  abundant  on  the  shores  of 
Lake  Superior,  and  many  Likes  and  rivers  of  the  west. 
Externally  the  agate  is  rough,  and  exhibits  no  sign  of 
the  beautifully  varied  appearance  it  will  present  when 
polished.* 


*  AGATE  MANUFACTURE. — The  most  celebrated  agate  quarries  are  at  Ober- 
stein,  Germany.  The  nodules  are  of  an  ashen-gray  color.  After  being  washed, 
they  are  placed  in  a  vessel  containing  honey  and  water,  which,  being  closely 
covered,  is  kept  in  hot  ashes  for  two  or  three  weeks.  The  stones  are  then  taken 
out,  cleansed,  immersed  in  sulphuric  acid,  and  then  roasted  a  second  time  in 
the  hot  ashes.  The  honey,  penetrating  the  pores,  is  carbonized  either  by  the 
long-continued  heat  or  the  action  of  the  acid.  The  depth  of  the  color  depends 
on  the  porosity  of  the  agate.  Some  become  perfectly  black,  others  take  a  rich 
brown  or  chocolate  tint,  some  are  striped  alternately  like  the  onyx,  while 
ethers  resist  all  attempts  to  change  the  natural  hue.  By  soaking  the  porous 
agates  in  a  solution  of  sulphate  of  iron,  and  then  heating  in  an  oven,  a  fine 


COMPOSITION     OF    THE     ROCKS  Jfi 

7.  Jasper  is  a  dull,  massive  variety  of  quartz,  with 
a  little  clay.  It  has  shades  of  red,  yellow,  brown,  and 
green,  owing  to  the  presence  of  iron  in  different  stages 
of  oxidation.  The  yellow  becomes  red  by  heat,  which 
changes  the  yellow  oxide  of  iron  to  red.  When  the  colors 
are  arranged  in  stripes,  it  is  termed  rMon  jasper.  It  is 
susceptible  of  high  polish,  and  is  therefore  much  prized 
for  ornamental  purposes.  When  of  a  deep  green,  with 
dark  red  spots,  it  is  named  Hood-stone.  At  Paris  there 
is  a  bust  of  Christ  carved  from  this  stone  in  such  a 
manner  that  the  red  spots  represent  the  drops  of  blood. 
A  hard,  velvet-black  jasper  is  called  the  touchstone.  It  is 
used  for  testing  the  purity  of  gold  alloys.  This  is  done 
by  rubbing  the  alloy  on  the  stone,  and  comparing  the 
color  with  that  of  some  known  alloy.  The  stone  is 
adapted  for  this  purpose  because  of  its  hardness  and 
smoothness,  and  also  because  it  presents  a  good  back- 
ground on  which  to  compare  colors. 

8.  Opal  is  a  very  beautiful  variety  of  quartz.  It 
contains  ten  per  cent,  of  water,  which  is  combined  with 
the  silica.  It  is  softer  than  quartz,  and,  unlike  it,  is 
easily  soluble  in  a  hot  solution  of  potash.  Its  external 
color  is  a  pure  white,  but  when  broken  it  exhibits  a  play 
of  rich  and  delicate  internal  reflection.  A  kind  called 


carnelian  red  is  produced.  A  blue  color,  which  has  all  the  effect  of  a  turquoise, 
is  also  developed  by  a  process  not  yet  divulged.  By  roasting,  the  natural  colors 
are  heightened  and  rendered  more  permanent.  In  these  various  ways  a  coarse 
and  valueless  stone  may  be  so  changed  as  to  pass  for  a  gem  of  the  first  quality 
The  agates  are  ground  on  rough  stones,  turned  by  water-power  from  the  numer- 
ous little  brooks  which  abound  in  that  neighborhood,  and  polished  on  soft 
wooden  wheels  with  powder  of  tripoli  (see  page  48)  found  near  by.  Vases,  cups, 
seals,  knife-blades,  agate  mortars  for  the  chemist's  use,  etc.,  are  made  in  such 
abundance  as  to  become  articles  of  commerce. 


46  LITHOLOGICAL      GEOLOGY. 

liydrophane  is  remarkable  for  becoming  transparent  when 
dipped  into  water.* 

9.  Sandy  'Pebbles,  Gravel,  Cobblestones,  etc., 

consist  largely  of  quartz,  since  it  resists  the  action  of  the 
water  longer  than  other  rock  materials.  The  color  is 
due  to  the  various  oxides  of  iron  ;  f  although  it  is  some- 
times a  mere  stain  produced  by  vegetable  matter. 

70 .  .Flint  is  a  compact  form  of  quartz  of  various 
colors — white,  brown,  and  even  black.  It  breaks  into 
fragments  having  a  sharp  edge  and  a  conchoidal  J  sur- 
face. Its  use  formerly  for  gun-flints  and  by  the  Indians 
for  arrow-heads  is  well  known. 

HORKSTONE  is  an  impure  variety  of  flint,  so  named 
from  its  color  and  appearance.  Buhrstone  is  a  kind  of 
flint  possessing  a  cellular  texture,  which  makes  its  sur- 
face very  rough.  In  many  of  the  best  stones  the  cavities 
equal  the  solid  portions.  It  is  found  in  various  States 


*  The  same  phenomenon  is  shown  in  an  ox's  eyeball.  When  plunged  into 
water,  it  vanishes  instantly  from  the  sight.  Both  refract  light  at  the  same  angle 
as  water,  and  hence  the  eye  has  no  power  of  distinguishing  them. 

t  Iron  is  Nature's  universal  dye.  Without  it  the  soil  would  be  a  dirty  white— 
the  color  of  snow  in  a  time  of  thaw.  Instead  of  the  pretty  lively  color  of  sand 
and  pebbles,  we  should  see  the  dull  and  somber  hue  of  ashes  ;  and  instead  of  the 
glittering  sand  of  the  sea  and  lake  shore,  a  plain  drab  or  gray,  which  no  wealth 
of  sunshine  or  of  spray  could  turn  to  beauty.  The  slates  used  for  roofing  have 
a  warm  rich  tint ;  oxide  of  iron  puts  vermillion  into  them  as  it  does  into  our 
bricks,  which  else  would  be  only  a  plain  pepper  and  salt.  The  ruddy  hues  of 
brown  now  seen  in  ploughing  sandy  fields,  contrasting  so  richly  with  the  green 
of  woods  and  meadow,  would  be,  without  the  iron,  only  the  cold  repulsive  gray 
of  clayey  soils.  Many  marbles,  too,  are  colored  with  this  same  familiar  dye. 
"  The  violet  veinings  and  variegations  of  the  marbles  of  Sicily  and  Spain,  the 
glowing  orange  and  amber  of  Sienna,  the  blood-red  color  of  precious  jasper 
that  enriches  the  temples  of  Italy,11  are  all  painted  with  iron-rust.  Thus  by  an 
infinity  of  design  does  God,  from  the  simplest,  commonest  material,  interweav- 
ing the  beautiful  in  Nature  everywhere,  cultivate  our  taste  and  adorn  the  world 
for  our  happiness. 

f  A  conchoidal  surface  is  one  that  is  curved  like  the  inside  ol  a  watch-crystal. 


COMPOSITION     OF     THE     ROCKS. 


47 


are  minute  one- 

FIG.  5. 


— Ohio,  Massachusetts,  Arkansas,  Georgia,  etc.  The 
buhrstone  of  Ohio  contains  some  lime,  and  it  has  been 
thought  that  the  cellular  character  may  be  due  to  the 
partial  dissolving  of  the  lime  out  of  the  stone. 

ORIGIN  OF  QUARTZ. — Though  quartz  is  a  mineral, 
probably  most  of  the  flint  and  hornstone  which  we  find 
is  of  animal  or  vegetable  origin.  Sponges  secrete  little 
spicules  or  points  of  silica. 
celled  vegetable  organisms, 
too  small  to  be  seen  singly 
by  the  naked  eye.  Yet  when 
gathered  in  countless  myri- 
ads, they  appear  as  a  brown  or 
reddish  slime.*  They  have 
the  power  of  separating  the 
silex  from  the  water  in  some 
unknown  way.  These  plants 
grow  in  such  numbers  that 
after  their  death  their  inde- 
structible siliceous  coverings 
so  accumulate  as  to  form 
strata  of  great  thickness  and 

Diatoms  Irom  Albany  and  WaterfordL 

extent.    The  hardness,  sharp-  Maine> 

ness,  minute  size  and  fragil- 
ity of  the  particles,  whereby 


B  is  magnified  25  Diameters. 
C  is  magnified  250  Diameters. 
D  is  magnified  200  Diameters. 


*  Dr.  Hooker,  in  his  account  of  the  Antarctic  regions,  says  :  "  Everywhere  the 
waters  and  the  ice  abounded  in  these  microscopic  vegetables.  They  stained  the 
iceberg  and  pack-ice  wherever  the  latter  was  washed  into  the  sea,  and  imparted 
to  it  a  pale  ocherous  color.  In  the  80th  deg.  of  S.  latitude,  all  the  surface  ice 
carried  along  by  currents,  and  the  sides  of  every  berg,  and  the  base  of  the  great 
Victoria  barrier  itself — a  perpendicular  wall  of  ice  from  one  to  two  hundred  feet 
above  the  sea  level — were  tinged  brown  from  this  cause,  as  if  the  waters  were 
charged  with  oxide  of  iron."  It  is  a  curious  fact  that  these  minute,  flint-secret- 
ing diatoms  are  the  food  of  the  soft,  almost  impalpable,  jelly  fish,  and,  as  has 
been  lately  stated,  that  this  in  turn  constitutes  the  food  of  the  huge  whale. 


" 


48  LITHOLOGICAL      GEOLOGY. 

they  fall  to  pieces  at  the  least  touch,  make  the  mass 
useful  as  a  polishing  material.  Tripoli,  or  polishing 
slate,  is  composed  of  these  siliceous  remains,  a  single 
cubic  inch  containing  41,000,000,  so  that  at  every  stroke 
made  with  the  powder  millions  of  perfect  fossils  are 
crushed  to  atoms.  The  mountain  meal,  or  fossil  farina 
of  Tuscany,  is  a  mass  of  these  organisms.  In  Lapland  a 
similar  earth  is  found,  winch  in  times  of  scarcity  the 
inhabitants  mix  with  the  ground  bark  of  trees,  and  use 
for  food.  This  infusorial  earth,  as  it  is  termed,  is 
found  at  various  localities  in  this  country,  as  at  Rich- 
mond, Va.,  Maidstone,  Vt.,  Waterford,  Me.,  etc.  At 
Bilin,  Bohemia,  besides  a  stratum  of  tripoli  14  feet 
thick,  a  kind  of  semr-opal  occurs,  composed  of  diatoms 
and  sponge  spicules,  cemented  with  siliceous  matter.  It 
is  thought  that  the  more  delicate  shells  were  dissolved 
by  the  water,  and  thus  formed  opal  cement,  in  which 
the  more  durable  of  the  fossils  are  preserved,  like  insects 
in  amber.  Flint  and  hornstone,  under  the  microscope, 
reveal  the  outlines  of  spicules  of  sponges,  of  diatoms, 
and  of  other  animalcules.  We  are  thence  led  to  believe 
that  perhaps  the  larger  part  of  the  quartz  we  find,  in 
all  its  Protean  forms,  has  impressed  upon  it  an  organic 
structure  which  it  received  at  an  inconceivably  remote 
time,  when  it  was  animated  by  microscopic  life. 

(a.)     ALUMINA. 

Alumina  is  the  oxide  of  the  metal  aluminum,  which, 
on  account  of  its  abundance  in  clay,  is  called  the 
"  clay  metal."  In  hardness,  alumina  is  inferior  only 
to  the  diamond,  and  will  easily  scratch  quartz.  Pure 


COMPOSITION     OF     THE     ROCKS. 


crystallized  alumina,  when  red,  constitutes  the  ruby. 
This  ranks  in  value  next  to  the  diamond,  and  some  per- 
fect specimens  have  sold  at  even  a  higher  rate.  The 
dull-colored  variety  is  called  corundum,  and  the  coarse 
granular  kind,  combined  with  magnetic  iron  ore,  emery. 
(See  feldspar  and  common  clay,  page  53.) 

(3.)     LIME. 

/.  Carbonate  of  Zdme  is  more  commonly  called 
"  limestone.'5 

(a.)  LIMESTONE  is  a  compound  of  lime  and  carbonic 
acid.  It  embraces  all  shades  from  white  and  cream  color 
to  a  dense  black.  .  It  may  be  known  by  its  softness — 
being  easily  scratched  with  a  knife — and  by  its  effer- 
vescing with  an  acid.  Limestone  is  useful  for  building 
purposes,  and  when  the  carbonic  acid  is  expelled  by  beat, 
quick-lime  is  produced. 

(b.)  CALC-SPAR   (Calcite).— Pure  crystals  of  limestone 
are  called  calc-spar.     They  readily  cleave  into  the  rhom- 
bohedral  form.     Trans- 
parent     crystals      are 
termed  Iceland  spar,  as 
the    best    are    brought 
from      that      country. 
They  beautifully  illus- 
trate double  refraction. 

(c.)  CHALK  is  a  por- 
ous, unCOmpacted   Vari-  Object  seen  through  Iceland  Spar. 

Crystal  from  Rossie,  N.  Y. 

ety  of  limestone. 

(d.)  CALCAREOUS  TUFA  *  is  formed  by  deposition  from 


FIG.  6. 


*  Calcareous  tufa,  or  travertine,  often  forms  beds  of  limestone,  which  can  be 

3 


60 


LITHOLOGICAL      GEOLOGY. 


water  charged  with  carbonate  of  lime  in  solution.  (Rev. 
Chem.,  page  138.)  Stalactites  depend  from  the  roof  of 
caverns  in  limestone  regions.  They  are  produced,  like 
tufa,  from  calcareous  waters.  The  water,  dripping  down 
from  crevices  in  the  rock,  evaporates,  deposits  its  lime- 
stone, and  thus  forms  pendants  of  curious  and  grotesque 
figures.  Some  hang  like  icicles,  while  others  look  like 
falling  sheets  of  water  caught  in  mid-air,  and  turned 
to  stone.  The  drippings  upon  the  floor  produce  calcare- 
ous mounds,  called  stalagmites.  The  two,  meeting,  often 
form  pillars  strangely  grouped  and  interwoven  like  trees 
in  a  forest,  and  sometimes  even  combined  into  broad 
curtains  of  semi-transparent  rock. 

*(e.)  OOLITE  (oon,  an  egg,  and 
litlios,  a  stone)  is  a  limestone 
consisting  of  numerous  small, 
rounded  grains,  resembling  the 
roe  of  a  fish. 

(f.)  MARL  is  a  mixture  of 
clay  and  carbonate  of  lime. 
It  is  loose,  friable,  and  gen- 
erally full  of  small  shells.  It 
is  valuable  as  a  fertilizer. 

OOlitic  Marble,  Chester,  England.  (g«)       MAGNESIAS'       LlME- 


FIG.  7. 


used  for  architectural  purposes.  The  Coliseum  at  Kome  is  built  of  this  rock. 
In  the  vicinity  of  Rome  a  solid  layer  of  this  stone,  a  foot  in  thickness,  has  been 
formed  in  four  months.  Springs  near  the  Tiber  are  famous  for  their  production 
of  travertine.  Indeed,  the  term  travertine  means  simply  Tiber  stone.  The  water 
of  the  river  near  them  is  so  charged  with  mineral  matter  that  it  is  said  that 
even  fish  have  been  entangled  and  petrified.  In  certain  regions,  springs  deposit 
the  tufa  so  readily  that  incrustations  may  be  obtained  upon  sticks,  leaves, 
baskets,  etc.  At  the  baths  of  San  Filipo,  Tuscany,  the  preparation  of  casts  in 
this  way  forms  a  regular  business.  Moss  petrified  in  this  manner  is  so  plenti- 
ful in  Caledonia.  N.  Y.,  that  it  is  used  for  building  fences.  It  is  also  found  in 
abundance  at  Chittenango  and  Sharon  Springs. 


COMPOSITION     OF    THE    ROCKS.  51 

STONE,  or  dolomite,  contains  magnesia.  It  is  harder 
than  limestone,  and  does  not  readily  effervesce  with  an 
acid  unless  heat  is  applied. 

(h.)  MARBLE  is  crystallized  limestone.  When  pure, 
it  is  clear  and  fine-grained,  like  loaf-sugar.  It  is  of 
great  value  in  the  arts.*  The  finest  statuary  marble 
comes  from  Carrara  and  the  island  of  Paros,  whence 
the  term,  Parian  marble,  so  famous  among  the  Greek 
sculptors.  The  pure  whiteness  of  Parian  marble  was 
thought  to  be  especially  pleasing  to  the  gods,  hence  it 
was  selected  for  the  work  of  Praxiteles  and  other  cele- 
brated artists.  The  Venus  de  Medici,  the  Oxford  mar- 
bles, and  many  noted  statues  are  wrought  from  this 
stone.  An  excellent  building  marble  is  quarried  at 
Rutland,  Vt.,  in  Massachusetts,  and  in  Connecticut. 
Marble  often  contains  mica  and  other  impurities,  which 
give  it  a  clouded  and  mottled  appearance.  This  de- 
tracts from  its  value,  and  ruins  it  for  statuary  purposes. 
Verde  Antique  is  a  variety  of  marble  streaked  with  ser- 
pentine. 

Marble  is  sawed  into  slabs  by  means  of  a  thin  iron 
plate,  a  saw  without  teeth,  driven  by  machinery.  The 
friction  is  produced  by  sharp  sand  and  water,  which  are 


*  What  are  marbles  made  for  ?  Over  the  greater  part  of  the  surface  of  the 
earth  we  find  that  a  rock  has  been  providentially  distributed  in  a  manner 
particularly  pointing  it  out  as  intended  for  the  service  of  man.  It  is  exactly 
of  the  consistence  which  is  best  adapt- d  for  sculpture  and  architecture.  It  is 
neither  hard  nor  brittle,  nor  flaky,  nor  splintery,  but  uniform  and  delicately, 
yet  not  ignobly  soft — exactly  soft  enough  to  allow  the  sculptor  to  work  it 
without  force,  and  trace  on  it  the  finest  lines  of  finished  form  ;  yet  it  is  so  hard 
as  never  to  betray  tbe  touch  or  moulder  away  beneath  the  steel ;  and  so  admi- 
rably crystallized  and  of  such  permanent  elements,  that  no  rains  dissolve  it,  no 
time  changes  it,  no  atmosphere  decomposes  it ;  once  shaped,  it  is  shaped  for- 
ever, unless  subjected  to  actual  violence  or  attrition.  This  rock,  then,  is  pre- 
pared by  Nature  for  the  sculptor  and  architect,  as  paper  is  by  the  manufacturer 
for  the  artist ;  nay,  with  greater  care  and  more  perfect  adaptation.  ~Rmkin. 


6%  LITHOLOG1CAL      GEOLOGY. 

constantly  applied.     The  saws  penetrate  very  slowly,  not 
more  than  an  inch  per  hour. 

ORIGIN  OF  LIMESTONE. — Limestone  forms  a  promi- 
nent constituent  of  shells,  bones,  corals,  etc.  Animals 
have  the  power  of  secreting  the  lime  from  the  water  in 
which  they  live,  or  from,  the  food  they  eat.  When  they 
die  their  mineral  remains  accumulate  in  great  quanti- 
ties, and  gradually  harden  into  rock.  Chalk  was  formed 
by  the  consolidation  of  minute  shells,  smaller  than  a 
grain  of  sand.  As  each  particle  is  thus  cellular,  and 
not  solid,  the  chalk  has  a  soft  porous  structure.  The 
microscope  reveals  these  tiny  shells  in  the  glazing  on  a 
visiting-card.  Even  when  the  rock  contains  no  trace 
of  fossils,  it  may  have  been  made  by  the  sea  breaking 
and  grinding  shells  and  corals  into  a  fine  powder,  just  as 
it  grinds  rock  and  pebbles  into  fine  sand.  We  see  this 
process  now  going  on  in  the  formation  of  coral-reefs,  as, 
for  example,  off  the  coast  of  Florida.  From  the  vast 
extent  of  the  limestone  rock  on  the  earth,  we  can  form 
some  estimate  of  the  amount  of  animal  life  which  has 
existed  in  past  ages. 

2.  Sulphate  of  Z<ime,  or,  as  it  is  generally  called, 
"  gyPsum>"  1S  a  compound  of  lime  and  sulphuric  acid. 

GYPSUM  is  readily  distinguished  from  limestone  by  its 
inferior  hardness.  It  may  be  scratched  with  the  finger- 
nail, and  carved  with  a  knife  into  any  desired  shape.  It 
does  not  effervesce  with  the  acids. 

(a.)  UNCRYSTALLINE  GYPSUM  is  commonly  known  as 
"plaster  stone."  When  the  stone  is  crushed  and  ground 
it  forms  a  white  powder  sold  as  plaster,  and  used  as  a 
fertilizer. 


COMPOSITION   OF   VHE  HOCKS.         53 

(b.)  CRYSTALLINE  GYPSUM  occurs  in  fibrous  masses 
with  a  pearly  lustre,  known  as  satin  spar ;  in  scales, 
layers,  and  crystals,  pellucid  as  glass,  selenite ;  and  as  a 
snowy-white  solid,  alabaster. 

At  Grand  Rapids,  Mich.,  a  mottled  variety  is  found, 
which  is  turned  in  a  lathe  into  beautiful  vases,  goblets, 
and  other  ornamental  objects.  In  the  mammoth  cave, 
Kentucky,  are  found  exquisite  forms  resembling  leaves, 
flowers,  and  vines.  When  burned,  gypsum  is  known  as 
"  plaster  of  Paris." 

(4.)    THE     SI  LICATES. 

The  Silicates  are  compounds  of  silica  with  other 
substances,  such  as  alumina,  lime,  magnesia,  potash, 
oxide  of  iron,  etc.  The  following  are  the  most  com- 
mon ones : 

/.  Feldspar.  This  is  somewhat  softer  than  quartz, 
and,  unlike  it,  has  a  cleavage  in  two  directions,  each 
crystal  showing  a  flat  surface  and  pearly  lustre.  It  has 
usually  a  white  or  flesh-red  color.  There  are  three  vari- 
eties which  are  silicates  of  alumina  with  an  additional 
substance,  viz  :  orthoclase  or  potash-feldspar,  albite  or 
soda-feldspar,  and  labradorite  or  lime-feldspar.  Albite 
(albus,  white)  may  always  be  distinguished  by  its  marked 
whiteness.  Labradorite  (originally  from  Labrador)  ex- 
hibits often  a  beautiful  play  of  colors  from  internal 
reflection,  and  is  susceptible  of  polish.  Clinkstone,  so 
named  because  of  the  metallic  ring  it  emits  when  struck 
with  a  hammer,  is  a  compact  variety  of  feldspar. 

COMMON"  CLAY  is  formed  by  the  decomposition  of  feld- 


54  LIT  SOL  0  G  1  CAL     GEOLOGY. 

spar  rocks  mixed  with  a  large  proportion  of  quarlz  sand. 
Pure  feldspar,  when  decomposed,  produces  kaolin  (from 
Kaoling,  the  name  of  a  locality  in  China,  where  it  is 
obtained),  a  kind  of  clay  used  for  making  porcelain  or 
China-ware.  The  red  color  of  bricks  is  due  to  the  iron 
contained  in  the  clay.  Pipe-clay  is  free  from  iron.  The 
beautiful  pipe-stone  used  by  the  Indians  was  a  compacted 
red  clay  from  Coteau  des  Prairies.  A  bed  of  similar  clay 
is  now  accumulating  in  Lake  Superior. 

2.  Mica  (micare,  to  glisten)  is  commonly  called 
"  isinglass."  It  is  easily  known  by  its  lustre  and  by  its 
separating  readily  into  thin  elastic  plates,  which  may 
again  be  subdivided  until  many  thousand  would  be  re- 
quired to  make  an  inch  in  thickness.  It  is  often  seen  in 
sand  as  bright,  glittering  particles.  On  account  of  its 
transparency  it  is  used  in  Siberia  for  windows.  It  is 
employed  on  board  of  ships  where  the  concussion  would 
be  liable  to  break  glass,  and  for  windows  in  stoves. 

3 '.  Hornblende  takes  the  first  part  of  its  name 
from  its  being  tough  like  horn,  and  the  second  (blenden, 
to  deceive)  from  its  sometimes  resembling  iron-ore.  It 
has  generally  a  black  or  greenish -black  color  and  a 
pearly  lustre.  Some  varieties  present  long,  slender, 
needle-shaped  crystals  of  a  delicate  green  tint  and  a 
glassy  lustre.  Asbestos  (unconsumed)  is  so  fibrous  that 
it  can  be  spun  and  woven  like  cotton.  The  ancients 
made  it  into  napkins,  which,  when  soiled,  were  cleansed 
by  being  thrown  into  the  fire,  where  they  were  burned 
clean  and  white  in  a  few  minutes.  The  Greenlanders 
use  it  for  lampwicks,  and  it  formerly  served  a  similar 


COMPOSITION     Off     THtf     ROCKS. 


Hornblende  Crystals  in  Quartz. 
Berkshire,  Mass. 


purpose  in  keeping  the  perpetual  fire  in  the  temples, 
its  incombustibility  being  thought  to  render  it  sacred. 
It  is  said  that  in  Siberia 
and  Spain,  gloves,  purses, 
etc.,  are  made  from  ami- 
anthus (undefiled),  a  vari- 
ety of  asbestos  having  a 
beautiful  satin  lustre.  The 
finest  locality  for  asbestos 
in  this  country  is  at  the 
Quarantine,  New  York. 

PYROXENE,  often  called 
augite  (from  auge,  lustre), 
is  a.  dark-green  mineral,  very  like  hornblende,  and  some 
of  its  massive  specimens  can  hardly  be  distinguished 
from  it.  Its  crystals,  however,  are  stouter  and  thicker, 
and  are  never  needle-shaped,  though  it  has  a  fibrous 
asbestos  which  can  hardly  be  distinguished  from  horn- 
blende except  by  analysis.  Augite  is  a  characteristic 
constituent  of  igneous  rocks. 

^.  Talc  is  so  soft  that  it  can  be  cut  with  a  knife, 
and  even  scratched  by  the  finger-nail.  It  separates 
readily  into  thin  pearly  layers,  which  are  not  elastic 
and  tough  like  those  of  mica.  It  has  usually  a  light- 
green  color,  and  feels  greasy  when  rubbed  with  the  finger. 
A  compact  variety  of  talc  is  familiarly  known  as  "French 
chalk." 

SOAPSTONE  or  steatite  (stear,  fat)  is  a  massive  crys- 
talline variety  which  is  susceptible  of  being  worked  into 
any  desired  form,  and  of  receiving  a  high  polish.  It  can 
be  sawed  into  slabs  or  turned  in  a  lathe.  It  is  made  into 


LITHOLOG1CAL     GEOLOGY. 


inkstands,  water-pipes,  culinary  vessels  and  fire-stones 
for  furnaces. 

SERPFNTISTE  contains  about  equal  parts  of  magnesia 
and  silica  with  12  per  cent,  of  water.  It  is  not  granular 
and  has  generally  a  dark-green  hue  and  a  dull,  resinous 
lustre.  It  was  named  from  its  mottled  colors,  resembling 
the  skin  of  a  serpent.  Stoves  have  been  made  of  it,  as  it 
bears  heat  well.  When  polished,  "  precious  serpentine  " 
has  a  rich,  oil-green  tint,  and  is  highly  valued  for  inlaid 
work. 

CHLORITE  is  a  mineral  somewhat  resembling  talc  and 
serpentine.  It  has,  however,  a  dark,  olive-green  color,  a 
granular  texture,  and  is  much  less  unctuous  to  the  touch. 
It  forms  a  slaty  rock  very  common  in  some  localities. 

5.    Garnet  is  a  common  mineral  in  connection  with 


FIG.  9. 


Garnets  in    Mica    Schist. 


FIG.  10. 


Tourmaline  Crystals  in  Quartz. 
Alexandria  Bay,  N.  Y.- 


mica,  hornblende,  and  gran- 
ite. It  is  found  usually  in 
dark-red  crystals  of  12  or 
24  sides.  This  dodccahe- 
dral  form,  and  its  fracture 
presenting  an  entire  want 
of  cleavage,  with  its  glassy 
lustre,  sufficiently  distin- 
guish it.  The  garnet  is  the 
ancient  carbuncle.  When 
clear-colored  it  is  a  beauti- 
ful gem. 

6.    To^lrma2^ne  is 

found  in  long  prisms  of  3, 
6,  9,  or  12  sides,  each  of 


CLASSIFICATION     OF     THE     ROCKS.        57 

which  is  quite  generally  furrowed  lengthwise.  It  is  of 
various  colors — black,  red,  green,  and  even  white.  The 
black  crystals  are  highly  polished,  have  no  cleavage,  and 
break  like  resin.  They  are  often  found  as  small  as  a 
knitting-needle,  and  several  inches  long,  radiating  in 
every  direction  through  the  rock  which  contains  them. 


II.     CLASSIFICATION    OF    THE    MOCKS. 


In  the  earth's  crust  we  find  two  kinds  of  rocks,  pro- 
duced respectively  by  the  action  of  fire  and  of  water. 
The  former  was  poured  out  from  the  furnace  within 
the  earth,  and  the  latter  spread  out  by  the  waters  above, 
These  two  agents,  fire  and  water,  seem  to  have  worked 
jointly  in  laying  the  solid  foundations.  Rocks  are  di- 
vided into  three  different  classes  according  to  their  mode 
of  formation  :  Sedimentary,  igneous,  and  metamorphic. 

(i.)    SEDIMENTARY    ROCKS. 

Sedimentary  ffiocks  are  those  which  have  been 
deposited  by  water.  They  are  arranged  in  strata  or 
layers,  and  are  hence  sometimes  called  the  stratified 
rocks.  They  comprise  the  following  kinds : 

/.  Sandstone  y  which  is  only  consolidated  sand,  and 
may  be  either  siliceous  or  argillaceous  (clayey). 

2 .  Conglomerate,  which  is  only  consolidated  gravel 
— the  conglomerate  taking  the  name  siliceous,  calcare- 


58  LIT  SOL  OGIGAL      GEOLOGY. 

ous,  or  ferruginous  (ferrum,  iron),  from  the  character 
of  the  sandy  paste  which  cements  together  its  pebbles. 
If  the  conglomerate  is  composed  of  rounded  pebbles,  it 
is  often  styled  a  "pudding  stone;"  if  of  angular  frag- 
ments, a  "  breccia  "  (bret'-cha).  The  Potomac  marble, 
seen  in  the  capitol  at  Washington,  is  a  very  beautiful 
calcareous  breccia. 

3  '.  Shale*  or  argillaceous  rock,  which  is  composed 
mainly  of  clay,  and  separates  easily  into  thin,  fragile, 
irregular  plates. 


,  which  consists  of  shells,  coral,  etc., 
pulverized  by  the  waves  or  precipitated  from  water  hold- 
ing lime  in  solution. 

Scenic  Description.  —  Sandy  regions,  from 
the  shifting  character  of  the  material,  must  be  some- 
times abruptly  uneven  and  irregular,  and  may,  there- 
fore, occasionally  afford  a  pleasing  diversity  ;  the  tend- 
ency, however,  is  to  a  flat  and  monotonous  surface. 
Shaly,  and  especially  slaty  formations,  consisting  usu- 
ally of  harder  and  softer  layers,  which  weather  unevenly, 
present  oftentimes  wild  ravines  and  picturesque  water- 
falls, as  in  the  Watkins  Glen,  near  Seneca  Lake,  N.  Y. 
The  streams  cut  deep  channels  and  make  abrupt 
plunges  with  unaccountable  leaps,  while  the  tops  of  the 
hills  form  escarpments  with  sharp  edges.  When  the 
clay  shale  is  more  uniform,  it  presents  a  scenery  less 
picturesque,  but  not  less  beautiful.  Gracefully  contoured 
hills  and  grass-carpeted  meadows  in  wide-spreading 
valleys  mark  the  softer  aspects  of  the  rural  landscape. 


CLASSIFICATION    OF    THE    ROCKS.  59 


(2.)    IGNEOUS    ROCKS. 

Jgneous  ^Rocks  are  those  which  have  been  thrown 
out  in  a  melted  state.  They  are  usually  not  arranged  in 
layers,  and  are  hence  termed  the  unstratified  rocks. 
They  are  divided  into  two  classes — trap  and  volcanic 
rocks. 

/.  Trap  ffiocks  are  so  called  from  the  Swedish 
word  trappa,  stairs,  because  they  frequently  occur  in 
terrace-like  bluffs,  in  the  form  of  massive  steps.  They 
are  generally  black  or  of  a  dark  color,  often  with  shades 
of  green  or  brown.  Their  hardness  renders  them  very  ser- 
viceable in  paving  and  "  macadamizing  "  roads,  for  which 
purpose  they  are  largely  used.  Their  dull  and  unattrac- 
tive hues,  and  the  difficulty  of  dressing  them  into  shape, 
unfit  them  for  general  purposes.  They  are,  however, 
very  appropriate  for  Gothic  edifices  on  account  of  the 
appearance  of  age  which  they  give.  There  are  four 
common  varieties  of  the  trap-rock. 

(a.)  BASALT  is  also  called  dolerite  (doleros,  deceptive), 
because  of  the  difficulty  in  distinguishing  its  constituent 
minerals.  These  are  principally  augite  and  feldspar.  It 
sometimes  contains,  scattered  through  it,  crystals  of  a 
bottle-glass  green  color,  called  chrysolite  (olivine).  When 
the  rock  weathers,  these  little  grains  fall  out.  They  may 
be  distinguished  from  glass  by  having  a  cleavage.  They 
are  used  as  gems,  though  they  are  quite  soft  and  have 
little  lustre. 

(K)  GREENSTONE — known  sometimes  as  "  ironstone"— 


60 


LITHOLOGICAL       GEOLOGY. 


FlG.   II. 


is  also  called  diorite  (dioros,  distinct),  because  its  com- 
position is  so  readily  determined.  It  consists  of  horn- 
blende and  feldspar.  Most  of  the  trap -rocks  of  the 
Eastern  States  are  diorite. 

(c.)  PORPHYRY  (porphura,  purple)  is  so  named  from 
a  purple  variety  which  was  highly  prized  in  Egypt.     It 

consisted  of  a  red  feldspar 
with  rose-colored  crystals 
scattered  through  it.  It 
was  susceptible  of  a  high 
polish,  and  was  very  en- 
during, hence  it  was  much 
sought  after  by  the  an- 
cients, who  wrought  it 
into  sepulchres,  baths, 
obelisks,  etc.  Any  trap- 
rock  in  which  the  feld- 
spar is  disseminated  in 
distinct  crystals  is  said 
to  be  porphyritic. 

(d.)  AMYGDALOID 
(amygdala,  an  almond)  is 
a  name  applied  to  trap- 
rocks  containing  cavities 
often  filled  with  quartz, 
calcite,  etc.,  so  that  a 
weathered  surface  of  the 
rock  appears  like  a  cake 
stuck  full  of  almonds. 


Lava  (Scoria),  in  part  turned  into  an 
Amygdaloid. 


Scenic   Description.— The  most  striking   char- 
acteristic of   the    trap-rocks  is  their    Columnar    struc- 


CLASSIFICATION     OF     THE     ROCKS.         61 

ture.*  They  are  crystallized  into  prisms  more  or  less 
regular,  with  from  three  to  eight  sides,  a  diameter  of 
from  one  inch  to  many  feet,  and  a  height  often  of  sev- 
eral hundred  feet.  These  pillars  are  frequently  jointed, 
and  the  sections  are  concave  at  the  top  and  convex  at  the 
bottom.  The  columns  often  stand  perpendicularly,  and 
when  broken  and  disintegrated  by  the  action  of  the 
weather  or  of  the  sea,  present  picturesque  appearances 
as  of  old  castles  and  of  ruined  fortifications.  Some 
of  the  most  remarkable  scenery  in  the  world  is  of  this 
character.  Fingal's  Cave,  Isle  of  Staffa,  and  the  Giant's 

FIG.  13. 


Fingal's  Cave.    (From  a  Photograph.) 


*  We  suppose  that  the  columnar  structure  of  trap-rocks  has  resulted  from  a 
port  of  crystallization  while  cooling  under  pressure  from  a  melted  state,  for  two 
reasons :  1,  similar  columns  are  found  in  recent  lavas ;  and,  2,  from  experiment. 
Mr.  Watt  melted  700  Ibs.  of  basalt,  and  caused  it  to  cool  slowly,  when  globular 
masses  were  formed,  which  enlarged  and  pressed  against  one  another  until  reg- 
ular columns  were  the  result. 

This  can  be  illustrated  by  putting  balls  of  putty  into  a  vessel,  and  gently  pressing 


62  LITHOL  OG  1C AL      GEOLOGY. 

Causeway*  in  the  north  of  Ireland,  are  familiar  exam- 
ples. On  the  north  shore  of  Lake  Superior,  among  the 
Palisades  on  the  Hudson,  upon  Mts.  Tom  and  Holyoke, 
Mass.,  along  the  banks  of  the  Columbia  Eiver,  and  the 
Penobscot  in  Maine,  are  presented  many  similar  scenes. 
Trap-rocks,  when  weathered,  acquire  a  dull,  dark  brown 
appearance,  and  are  often  colored  with  patches  of  white 
lichens.  There  are  cases  of  the  existence  of  basalt  in 
well-defined  flows,  which  still  adhere  to  craters  visible  at 
the  present  day,  and  in  regard  to  the  igneous  origin  of 
which  there  can  be  no  doubt.  One  of  the  most  striking 
examples  of  a  basaltic  crater  is  that  of  La  Coupe  in  the 
south  of  France.  Upon  the  flank  of  this  mountain,  the 
traces  left  by  the  current  of  liquefied  basalt  are  still  seen 
occupying  the  bottom  of  a  narrow  valley,  except  at  those 
places  where  the  river  Volant  has  cut  away  portions  of 
the  lava.  Trappean  regions  abound  in  perpendicular 
walls,  sharp  ascents,  and  abrupt  precipices.  The  erup- 
tive masses  often  rise  from  amid  level  plains,  while  hard 
dikes  alternate  with  rich  strata  which  decompose  into 


upon  them,  when  they  will  be  seen  to  arrange  themselves  in  five  and  six-sided 
columns,  precisely  similar  to  the  five  and  six-sided  columns  of  Staffa  or  the 
Giant's  Causeway.— Page. 
*  Hogg,  the  "  Ettrick  Shepherd,"  thus  graphically  refers  to  these  grandeurs 

of  Nature : 

"Awed  to  deep  silence,  they  tread  the  strand 
Where  furnaced  pillars  in  order  stand  ; 
All  framed  of  the  liquid  burning  levin, 
And  bent  like  the  bow  that  spans  the  heaven ; 
Or  upright  ranged,  in  wondrous  array 
With  purple  of  green  o'er  the  darksome  gray. 
The  solemn  rows  in  that  ocean  den 
Were  dimly  seen  like  the  forms  of  men ; 
Like  giant  monks  in  ages  agone. 
Whom  the  god  of  the  ocean  had  seared  to  stone  ; 
And  their  path  was  on  wondrous  pavement  old 
In  blocks  all  cast  in  some  giant  mould." 


CLASSIFICATION     OF     THE     ROCKS.        6$ 

fertile  soils.  The  soft  plain  ascends  often  at  one  stride 
into  a  hill  fantastically  rugged  ;  and  bare,  fractured 
precipices  overtop  level  fields  and  terraced  slopes  rich  in 
verdure.* 

2 .   Volcanic  ffiocfcs  are  of  two  common  varieties. 

(a.)  TRACHYTE  (trachus,  rough)  is  so  named  because 
of  its  rough,  gritty  feel.  It  is  porous,  has  a  white,  gray, 
or  black  color,  and  is  usually  porphyritic.  It  is  abundant 
in  South  America — the  colossal  Chimborazo  being  a  lofty 
trachytic  cone — in  the  extinct  volcanic  regions  of  the 
west,  on  the  banks  of  the  Ehine,  and  in  France. 

(b.)  LAVA  is  a  term  applied  to  all  melted  matter 
observed  to  flow  in  streams  from  volcanoes.  It  consists 
almost  entirely  of  augite  (pyroxene)  and  feldspar,  f  The 
former  constitutes  dark  colored,  and  the  latter  light  col- 
ored lava.  When  cooled,  the  upper  part  of  the  stream 
is  light  and  porous  as  a  sponge,  from  the  expansion  of 


*  Hugh  Miller  has  mentioned  the  curious  fact  that  all,  or  nearly  all,  the  noterf 
Scottish  fortresses  are  built  upon  trappean  rocks.  Thus  the  early  geologic 
history  of  a  country  seems  typical  of  its  subsequent  civil  history.  A  stormy 
morning,  during  which  its  strata  have  been  tilted  into  abrupt  angles  and  yawn- 
ing chasms,  is  generally  succeeded  by  a  stormy  day  of  fierce  wars,  protracted 
sieges,  and  all  the  turmoil  of  human  passion.  Amid  the  centers  of  disturbance, 
the  natural  strongholds  of  the  earth,  the  true  battles  of  the  race  have  been 
fought.  Greece,  the  Holy  Land,  the  Swiss  Cantons,  Scotland,  New  England, 
all  have  been  grand  theatres  alike  of  geologic  and  of  patriotic  strife. 

t  Other  simple  minerals  occur  in  lava.  At  least  100  species  have  been  de 
tected  in  that  of  Vesuvius,  but  they  bear  so  small  a  proportion  to  the  whole 
mass  as  to  render  it  incompatible  with  the  design  of  this  work  to  devote  spac* 
to  them  here.  There  are  al  10  thrown  out  from  volcanoes  "  fragments  of  gran- 
ite and  other  rocks  scarcely  altered ;  cinders  and  ashes  of  various  degrees  of 
fineness,  which  are  sometimes  converted  into  mud  by  the  water  that  accom- 
panies them  ;  also  sulphur  in  a  pure  state ;  various  salts  and  acids  ;  and  several 
gases,  among  which  are  the  hydrochloric,  sulphurous,  and  sulphuric  acids ; 
alum,  gypsum,  sulphates  of  iron  and  magnesia,  chlorides  of  sodium  and  potas- 
sium, of  iron,  copper,  and  cobalt ;  chlorine,  nitrogen,  sulphuretted  hydrogen/1 
eta.—  Hitchcock. 


66 


LITHOLOGICAL      GEOLOGY. 


the  steam  bubbles,  and  will  swim  in  water,  while  the  lowei 
portions  are  hard  and  compact  like  the  ancient  basalt. 
The  porous  lava  is  called  scoria.  Pumice  is  a  feldspathic 
scoria  with  long,  slender  air-cavities,  drawn  out  by  the 
forward  movement  of  the  lava  stream;  large  quantities 
of  it  are  often  found  floating  in  the  ocean.  It  is  much 
used  in  polishing  marble.  Obsidian  is  a  glassy-like  lava. 

Scenic  Description.— Regions  of  frequent  vol- 
canic action  contain  cones  and  craters  surrounded  by 
beds  of  lava  and  scoria.  These  features  are  well  exhibited 
in  the  accompanying  view  of  a  scene  near  Mono  Lake, 
Sierra  Nevada  region. 

FIG.  15. 


Volcanic  Cones,  near  Mono  Lake. 


(3.)     METAMORPHIC     ROCKS. 

Jtfelamorphic   ffiocfcs  are  those  which  have  been 
altered  by  heat,  moisture,  and  pressure.    Lava  penetrating 


CLASSIFICATION    OF    THE    ROCKS.        67 

sedimentary  rocks  would  materially  modify  their  char- 
acter ;  the  clay  would  be  changed  to  slate,  the  limestone 
converted  into  marble,  earthy  sandstone  and  clay  rocks 
into  granite-like  rocks,  and  the  impurities  crystallized 
into  various  minerals.*  The  stratification  would  be  de- 
stroyed, and  the  fossils  in  part,  if  not  entirely,  obliter- 
ated. Sometimes,  however,  the  original  fossils  may  be 
still  distinguished.  There  is  a  kind  of  marble  found  at 
Kilkenny  which  contains  shells  of  the  ammonite.  They 
look  exactly  like  the  prints  of  a  cureless  heel,  and  many  a 
housekeeper  has  wearied  herself  in  vainly  trying  to  scour 
out  these  fossil  remains.  The  famous  Carrara  marble  is  a 
metamorphic  limestone.  On  examination  with  a  lens  it 
reveals  spangles  of  graphite,  and  frequently  nodules  of 
ironstone  lined  with  perfectly  limpid  crystals  of  quartz. 
These  accidental  defects,  resulting  from  impurities  in  the 
limestone,  are  very  annoying  to  the  sculptor,  since  noth- 
ing in  the  exterior  of  a  block  betrays  their  existence. 

/.  Granite  (from  granum,  a  grain,  because  of  its 
granular  structure)  consists  of  feldspar,,  inica,  and  quarjbz. 
The  feldspar  shows  a  smooth  surface  of  cleavage  in  two 
directions,  and  is  usually  of  a  white  or  flesh  color ;  the 
mica  may  be  readily  recognized  by  its  glistening  look, 


*  In  Whitney's  Geological  Survey  of  California,  constant  illustrations  are 
given  of  the  effects  of  metamorphism.  Places  were  found  where  the  line  of 
separation  between  the  sedimentary  and  metamorphic  rocks  is  sharply  drawn. 
Near  the  junction  of  the  two  kinds,  the  latter  seem  to  have  Detained  their  origi- 
nal stratification.  Patches  of  sedimentary  rocks  which  entirely  escaped  the 
igneous  action  are  inclosed  in  the  metamorphic  rocks.  Here  is  a  layer  of 
quartz,  which  beyond  is  converted  into  jasper ;  a  clayey  sandstone  into  set. 
pentine,  or  into  mica  slate  with  disseminated  garnets.  The  metamorphic  and 
sedimentary  rocks  give  each  a  distinctive  character  to  the  landscape.  The 
former  furnish  hills  of  sharper  outline,  richer  soil,  and  more  abundant  vegeta- 
tion, so  as  to  be  readily  recognized  even  at  a  distance. 


68 


LITSOLOGICAL      GEOLOGY. 


FlG.   16. 


Graphic  Granite,  Berkshire,  Mass, 


and  by  being  easily  separated  into  thin  layers ;  the 
quartz  has  a  glassy  lustre  and  no  cleavage.  Graphic 
granite  is  a  variety  in  which  the  quartz  is  imperfectly 
crystallized  into  long,  slender  crystals.  When  the  rock 
is  broken  crosswise,  the 
ends  of  these  crystals  pre- 
sent forms  somewhat  re- 
sembling Hebrew  charac- 
ters. Sometimes  granite 
has  a  very  coarse  struc- 
ture, the  crystals  being  a 
foot  or  more  in  diameter ; 
at  other  times  it  is  so  fine 
that  one  can  with  diffi- 
culty distinguish  the  con- 
stituent minerals.  When  sound,  it  is  an  excellent  build- 
ing stone,  but  does  not  merit  the  character  of  extreme 
hardness  which  is  proverbially  ascribed  to  it.  Its  granu- 
lar texture  unfits  it  for  road-making,  since  it  is  crushed 
into  dust  so  readily  by  tramping  feet.  In  the  Crimean 
war  it  was  shown  that  granite  ramparts  were  as  easily  de- 
molished as  those  of  limestone.  Granite  seems  to  be  the 
lowest  rock  in  the  earth's  formation,  and  yet,  strangely 
enough,  it  is  found  on  Mt.  Blanc — the  highest  in  Europe, 
and  crowns  many  of  the  Rocky  Mountains. 

Granite  is  quarried  in  great  quantities  in  the  East- 
ern States  for  building  purposes.  New  Hampshire  and 
Massachusetts  are  noted  for  their  extensive  beds.  They 
may  be  called  the  Granite  States  of  the  Union.  The 
granite  is  detached  in  blocks  by  drilling  a  series  of 
holes,  one  every  few  inches,  to  a  depth  of  three  inches, 
and  then  driving  in  wedges  of  iron  between  steel  cheeks. 


CLASSIFICATION    OF    THE   ROOKS.  69 

In  this  manner,  masses  of  any  size  are  split  out.  There 
is  a  choice  of  direction,  as  the  granite  has  certain  direc- 
tions of  •  easiest  fracture.  Masses  120  feet  in  length  have 
been  obtained  at  some  of  the  quarries.  Granite  was 
highly  prized  by  the  ancients.  There  are  granite  obel- 
isks in  Egypt  which  have  stood  for  3,000  years.  Pom- 
pey's  Pillar  and  several  of  the  principal  Pyramids  are 
composed  of  this  material. 

FORMATION  OF  GRANITE. — Granite  is  often  styled  the 
primitive  rock,  since  it  seems  to  be  the  one  which  consti- 
tutes the  basement  of  the  earth's  crust.  Though  it  may 
now  lie  at  the  foundation,  it  may  still  be  a  metamorphic 
rock,  and  not  the  first  product  of  the  slowly  cooling 
globe.  It  is  more  likely  that  most  of  the  granite  rocks 
have  resulted  from  the  wearing  down  of  the  primeval 
crust  of  true  igneous  rocks.  These  were  carried  into 
the  sea  and  deposited  as  stratified  rock.  Buried  after- 
ward beneath  vast  accumulations  of  other  rocks,  by  the 
internal  heat  and  the  influx  of  hot  water  charged  with 
various  chemical  agents,*  they  were  crystallized,  and 
their  fossils  and  stratification  obliterated.  Again,  they 
may  have  been  worn  by  the  sea,  deposited,  and  afterward 

*  In  the  account  given  of  the  Pluton  Geysers,  California,  we  seem  to  have  an 
insight  into  the  laboratory  of  the  world,  and  can  learn  something  of  the  chemi- 
cal changes  which  have  been  going  on  in  past  ages.  These  geysers  are  hot 
springs,  which  throw  out  intermittingly  and  spasmodically  powerful  jets  of 
steam  and  scalding  water,  their  temperature  varying  from  93°  to  169°  P.  The 
water  contains  sulphuric  acid,  sulphuretted  hydrogen,  and  probably  other  active 
solvents.  The  rocks  are  rapidly  dissolving  under  this  powerful  metamorphic 
action.  Porphyry  and  jasper  are  transformed  into  a  kind  of  potter's  clay.  Trap 
and  magnesian  rocks  are  consumed,  much  like  wood  in  a  slow  fire,  forming  sul- 
phate of  magnesia  and  other  products.  Granite  is  rendered  so  soft  that  one  can 
crush  it  between  his  fingers  as  easily  as  unbaked  bread.  The  feldspar  is  con- 
verted partly  into  alum.  The  boulders  and  angular  fragments  brought  down  the 
ravine  by  floods  are  being  converted  into  a  firm  conglomerate,  so  that  it  is  diffi- 
cult to  dislodge  even  a  small  pebble,  the  pebble  itself  sometimes  breaking  before 
the  cement  will  yield.—- Sfiepherd,  Am,  Journ,  qf  Science* 


70  L1TBOLOGICAL      GEOLOGY. 

metamorphosed.  How  many  times  this  cycle  of  change 
has  taken  place,  we  have  no  way  of  judging.  The  entire 
crust  of  the  enrth  has  doubtless  undergone  metamorphic 
action,  to  some  extent  at  least,  and  is  unlike  what  it  was 
when  created.  What  made  up  that  primeval  crust  we  do 
not  know,  and  hence  cannot  tell  whether  any  of  the 
ancient  formation  survives.  It  is  generally  believed  that 
granite  could  not  be  produced  directly  by  the  cooling  of 
the  melted  lava  that  then  composed  the  globe.  There 
are,  however,  places  where  it  has  been  found  at  a  great 
depth,  and,  by  some  powerful  convulsion,  has  been  ejected 
to  the  surface  in  a  melted  state,  like  a  true  igneous  rock. 
It  may  even  now  be  in  the  process  of  formation  in  the 
lower  portions  of  the  earth's  crust.  It  is  certain  that  as 
the  crust  wears  away  above,  new  rocks  must  be  cooling 
underneath,  since  the  point  of  fusion  is  constantly  pass- 
ing downward.  Granite  has,  however,  been  formed  in  all 
ages  of  the  world,  and  cannot  be  thought  a  primitive 
rock  merely,  although  specially  characteristic  of  the 
earlier  periods.  We  shall,  therefore,  consider  it,  in  gen- 
eral, as  a  metamorphic  rock  crystallized  by  the  combined 
action  of  heat,  water,  and  other  chemical  agents,  from  sedi' 
mentary  or  more  ancient  rocks. 

Scenic  Description.  —  The  ancient  granite, 
having  been  exposed  for  so  long  a  time  to  the  wear  of 
the  elements,  rarely  imparts  boldness  or  grandeur  to  the 
landscape,  unless  more  recent  convulsions  have  broken  it 
up  and  rendered  it  picturesque.  When  containing  little 
feldspar,  and  being  therefore  more  durable,  it  forms  lofty 
pyramidal  peaks  of  sharp  outline  that  rise  in  enormous 
Bpires,  as  in  the  vicinity  of  Mt.  Blanc.  There  seems  to 


CLASSIFICATION     OF     THE     ROCKS.        H 

be  often   a  tendency  to   rounded  concentric   outlines,* 
which  render  the  view  sombre  and  uninteresting.    The 


FIG.  17. 


North  Dome— Yosemite  Valley. 

peculiar  dome-like  appearance  of  granite  mountains  is 
beautifully  illustrated  in  the  magnificent  scenery  of  the 

*  Humboldt  says :  "  All  formations  are  common  to  every  quarter  of  the  globe, 
and  assume  the  like  forms.  Everywhere  basalt  rises  in  twin  mountains  and 
truncated  cones  ;  everywhere  trap  porphyry  presents  itself  to  the  eye  under  the 
form  of  grotesquely  shaped  masses  of  rock ;  while  granite  terminates  in  gently 
rounded  summits."  As  the  pupil  will  observe,  however,  this  latter  is  but  one 
of  the  aspects  which  trranite  present*. 


72  LITHOLOGICAL      GEOLOGY. 

^Yosemite.  Its  colossal  peaks  are  of  solid  granite,  the 
^  North  Dome  being  3568  feet  in  height.  Granite  forms, 
in  general,  lofty  hills  and  elevated  table-lands,  which  are 
rendered  still  more  bleak  and  forbidding  by  the  snow- 
clad  peaks  of  the  more  elevated  mountains.  The  soil  is 
generally  scanty  and  barren.  The  clay  from  the  decom- 
posed granite  is  the  finest  and  best  that  can  be  found ; 
the  sand,  often  of  the  purest  white,  always  lustrous  and 
bright.  As  a  result,  the  landscape  wears  a  peculiar 
aspect  of  purity.*  It  cannot  become  muddy,  foul,  or 
unwholesome.  The  streams  may  indeed  be  opaque  and 
white  as  cream  with  the  churned  substance  of  the  weath- 
ered granite ;  but  the  water  is  good  and  pure,  and  the 
shores  not  slimy  nor  treacherous,  but  pebbly  or  of  firm 
and  sparkling  sand.  The  quiet  springs  and  lakes  are  of 
exquisite  clearness,  and  the  sea,  which  washes  a  granite 
coast,  is  as  unsullied  as  a  flawless  emerald. 


2.  Gneiss  (nice)  differs  from  granite  only  in  being 
stratified.  Indeed,  the  two  kinds  of  rock  pass  into  each 
other  so  insensibly  that  they  are  often  difficult  to  dis- 


*  It  is  remarkable  how  this  intense  purity  in  the  country  seems  to  influence 
the  character  of  the  inhabitants.  It  is  almost  impossible  to  make  a  cottage  built 
in  a  granite  country  look  absolutely  miserable.  Rough  it  maybe,  neglected, 
cold,  full  of  aspect  of  hardship,  but  it  never  can  look  foul ;  no  matter  how  care- 
lessly, how  indolently  its  inhabitants  may  live,  the  water  at  their  doors  will  not 
stagnate,  the  soil  at  their  feet  will  not  allow  itself  to  be  trodden  into  elime  ;  they 
cannot  so  much  as  dirty  tbeir  faces  or  hands  if  they  try.  Do  the  worst  they  can, 
there  will  still  be  a  feeling  of  firm  ground  under  them  and  pure  air  about  them, 
and  an  inherent  wholesomeness  which  it  will  need  the  misery  of  years  to  con- 
quer. The  inhabitants  of  granite  countries  have,  too,  a  force  and  healthiness  oi 
character  about  them,  abated  or  modified  according  to  their  other  circumstances 
of  life,  that  clearly  distinguish  them  from  the  inhabitants  of  less  pure  di»- 
tricts.— Euskin. 


CLASSIFICATION     OF    THE    ROCKS.         7$ 

tinguish.*  Its  origin,  therefore,  is  doubtless  the  same  as 
that  of  granite,  both  being  made  from  stratified  rocks ; 
when  the  stratification  entirely  disappeared,  granite  being 
the  result ;  and  when  only  partially  or  not  at  all,  gneiss. 
Because  of  the  ease  with  which  it  divides  into  thin  layers, 
this  rock  is  much  used  for  flagging. 

Scenic  Description. — In  our  own  country  we 
find  much  of  the  grand  scenery  of  the  White  Moun- 
tains, Blue  Eidge,  and  Rocky  Mountains,  among  rocks 
of  this  formation.  Hugh  Miller,  humorously  speaking 
of  the  gneiss  hills  of  Scotland,  says  :  A  gneiss  hill  is 
usually  massive,  rounded,  broad  of  base,  and  withal 
somewhat  squat,  as  if  it  were  a  mountain  well  begun, 
but  interdicted  somehow  in  the  building,  rather  than  a 
finished  mountain.  It  seems  almost  always  to  lack  the 
upper  stories  and  the  pinnacles.  It  is,  if  I  may  so  ex- 
press myself,  a  hill  of  one  heave ;  whereas  all  our  more 
imposing  Scottish  hills — such  as  Ben  Nevis  and  Ben 
Lomond — are  hills  of  at  least  two  heaves ;  and  hence  in 
iourneying  through  a  gneiss  district,  there  is  a  frequent 
feeling  on  the  part  of  the  traveler  that  the  scenery  is 
incomplete,  but  that  a  few  hills,  judiciously  set  down 
upon  the  tops  of  the  other  hills,  would  give  it  the 


*  Doubtless*  some  gneiss  has  been  formed  by  the  action  of  water,  and  is  per- 
haps a  sedimentary  rock.  Thus  granite  being  worn  away  by  the  waves,  the 
granite  debris  would  be  deposited  in  regular  strata  at  the  bottom  of  the  sea, 
constituting  gneiss.  Most  of  it  is,  however,  the  product  of  an  incomplete  meta- 
morphic  action,  which,  if  made  complete,  would  have  produced  true  granite  by 
destruction  of  all  fossils  and  stratification.  Thus  Dawson,  in  his  Acadian 
Geology,  says  that  in  Nova  Scotia,  near  the  Nictaux  river,  there  are  beds  of 
blate  in  which  the  granite  has  been  intruded,  and  the  slates  near  the  junction 
have  been  altered  into  gneiss  containing  garnets.  Here  is  a  case  of  clear  meta- 
inorphism  of  shale  into  gneiss. 


74  L1THOLOG10AL      GEOLOGY. 

proper  finish.    No  hill,  however,  accomplishes  more  with 
a  single  heave  than  a  gneiss  one. 

.       3.  Mica  Schist  is  a  gneiss  rock,  consisting  mostly 
'  of  mica.    The  dust  in  the  roads  of  places  abounding  in 
this  rock  is  full  of  the  fine  glistening  particles  of  mica. 

Scenic  Description.— The  scenery  of  regions 
where  mica  schist  predominates  is  bold,  rugged,  and 
unfertile.  Thrown  into  lofty  mountains  by  the  pro- 
truding granite,  and  often  tilted  in  nearly  vertical  posi- 
tions, they  present  that  rugged  and  abrupt  aspect  so 
characteristic  of  the  Scottish  highlands  and  some  of 
the  mountain  ranges  of  our  own  country.  Loch  Kat- 
rine and  many  other  places,  classic  for  their  picturesque 
beauty,  owe  their  origin  to  the  peculiarities  of  this  for- 
mation. Hugh  Miller  says:  "Their  gray  locks  of  silky 
lustre  are  curved,  wrinkled,  contorted,  so  as  to  remind 
us  of  pieces  of  ill-laid-by  satin,  that  bear  on  their  crushed 
surfaces  the  creases  and  crumplings  of  a  thousand  care- 
less foldings." 

.  <£.  Syenite  is  a  granite  in  which  the  mica  is  re- 
) placed  by  hornblende.  It  is  so  called  from  the  city 
of  Syene,  Upper  Egypt,  where  the  ancient  Egyptians 
quarried  it  for  monumental  purposes.  The  granite  found 
near  Aberdeen,  Scotland,  and  extensively  imported  into 
this  country,  is  of  this  class.  It  possesses  great  strength, 
a  half-inch  cube  requiring  to  crush  it,  a  pressure  of 
24,556  pounds.  The  celebrated  Quincy  granite  is  also  a 
syenite.  Many  public  edifices  are  built  of  this  stone; 
for  example,  the  Bunker  Hill  monument,  the  custom- 


CLASSIFICATION     OF     THE     ROCKS.         75 

houses  at  Boston  and  New  Orleans,  and  the  Astor  House 
in  New  York. 

5 '.  Quarlzite  is  a  rock  composed  of  quartz  sand 
cemented  by  heat.  In  a  quartz  district,  because  of  the 
slow  weathering,  the  hills  present  a  scenery  of  savage 
wildness,  but  wonderful  grandeur. 

6.  Marble  is  metamorphosed  limestone.  The  dif- 
ferent varieties  have  already  been  described  on  page  51. 
Limestone  is  one  of  the  rocks  in  which  the  metamor- 
phic  action  can  most  easily  be  traced.  When  not  thus 
modified  we  find  it  as  common  limestone,  chalk,  etc. 
By  heat  its  character  is  entirely  changed ;  it  takes  on 
a  crystalline  structure,  its  color  is  varied,  the  fossils  are 
generally  destroyed,  and  the  various  impurities  form  new 
minerals  which  often  fill  the  veins  of  the  marble  with 
beautiful  colored  figures,  as  seen  in  the  variegated  mar- 
bles of  California. 

There  are  also  other  varieties  of  metamorphic  rocks, 
viz.,  talcose  schist,  a  slate  which  contains  much  talc,  chlo- 
rite schist,  one  which  contains  chlorite  (an  olive-green 
mineral  very  like  talc),  and  slate  rock,  which  passes  almost 
insensibly  into  an  argillaceous  or  clayey  shale. 


m.    STRUCTURE  OF  THE  ?KOCKS. 

The  rocks  of  the  earth's  crust  are  divided  according 
to  their  structure  into  two  classes,  the  stratified  and  the 
unstratified  rocks.  The  former  are  arranged  in  layers, 
the  latter  are  not.  The  former  were  generally  produced 


76  LITHOLOGICAL      GEOLOGY. 

by  aqueous,  the  latter  by  igneous  agencies.  The  former 
mark  the  periods  of  rest  in  the  world's  history,  the  lat- 
ter chronicle  its  convulsions.  Upon  the  exterior  of  the 
crust  the  stratified  rocks  are  largely  in  excess,  occupy- 
ing probably  Jg  of  the  surface;  upon  the  interior,  how- 
ever, the  unstratified  comprise  the  whole  mass,  and  ex- 
tend to  a  depth  of  perhaps  50  miles.  Historical  geology 
deals  almost  entirely  with  the  stratified  rocks,  and  nearly 
all  of  its  principles  are  based  upon  facts  which  they  dis- 
close. 

(i.)     STRATIFIED     ROCKS. 

As  soon  as  dry  land  was  formed,  it  began  to  be  worn 
away  by  the  ceaseless  action  of  the  rain  and  the  restless 
sea,  depositing  the  debris  at  the  bottom  of  the  ocean.* 
Thus,  while  the  earth's  crust  has  been  growing  from 
below  by  the  formation  of  unstratified,  it  has  been  grow- 
ing above  by  the  formation  of  stratified  rocks.  These 
materials  are  arranged  in  comparatively  flat  layers  as  in 
Fig.  18.  In  this  way  the  earth  would  be  covered  over 
by  successive  deposits  like  the  coats  of  an  onion. 

FIG.  18. 


Sea 


/.    dislocations    of  Strata. — Had    these   wrap- 


*  It  is  probable  also  that  submarine  volcanoes  poured  their  liquid  streams 
into  the  primeval  ocean.  These  materials  were  worked  over  and  deposited  as 
stratified  rocks.  The  earliest  strata,  says  Agassiz,  are  pierced  with  numerous 
funnels,  which  were  outlets  for  the  fierce  floods  beneath. 


STRUCTURE     OF     THE     ROCKS. 


77 


pings  remained  undisturbed,  we  could  have  made  little 
progress  in  deciphering  their  history,  since  we  have  not 
pierced  the  crust  much  more  than  half  a  mile  in  perpen- 
dicular line.  But  by  igneous  action,  the  rocks  which 
would  have  lain  as  in  Fig.  18  have  been  upheaved,  and 
present  a  form  similar  to  that  shown  in  Fig.  19,  where 

FIG  19. 


we  can  examine,  on  the  top,  the  edges  of  various  sedi- 
mentary strata,  and  also  the  igneous  rocks  which  were 
hidden  below.  Oftentimes  the  geologist,  in  tracing  the 
course  of  a  river,  will  find  successive  strata  tilted  up  on 
edge,  presenting  the  appearance  represented  in  Fig.  20. 

FIG.  20. 


Here,  had  the  rocks  remained  in  their  original  position, 
the  river  in  its  descent  might  not  have  disclosed  more 
than  two  or  three  layers ;  now,  by  the  outcropping,  as  it 
is  termed,  many  successive  strata  can  be  examined  often- 
times within  a  few  miles. 


78 


LITHOLOGICAL      GEOLOGY. 


2.  ^Definitions. — A  stratum  includes  one  or  more 
layers,  or  laminae,  of  any  particular  kind  of  rock.  A  for- 
mation is  composed  of  several  strata  which  were  deposited 
in  the  same  period.  A  group  is  a  part  of  a  formation, 
including  such  strata  as  are  in  any  way  related  to  one 
another.  The  laminae,  or  layers,  of  a  group  bear  the  same 
relation  to  one  another  that  the  groups  of  a  formation  do. 

In  Fig.  21  the  strata  at  A  are  said  to  be  horizontal, 

FIG.  21. 


those  at  B  inclined  (and  the  angle  which  they  form 
with  the  horizon  is  called  the  dip),  those  at  E  to  be 
tilted  up,  at  C  to  be  vertical,  and  at  D  to  be  contorted. 
In  Fig.  22,  strata  dipping  in  opposite  directions,  «,  are 


FIG.  22. 


called  anticlinal;  when  dipping  toward  each  other,  s, 
synclinal ;  e  is  an  escarpment  or  a  bluff;  strata,  as  c, 
coming  to  the  surface,  are  called  an  outcrop ;  strata 
arranged  regularly  above  one  another,  as  at  o,  are  said 


STRUCTURE     OF     THE     ROCKS.  79 

to  be  conformable;  those  not,  as  at  x,  are  styled  un- 
conformable. 

3.    ^Diverse   Stratification. — Sedimentary  rocks 
were  not  always  originally  deposited  in  horizontal  layers. 

FIG.  23. 


Diverse  Stratification. 

Along  the  sea-shore  we  can  see  the  deposits  being  made 
on  its  sloping  bottom.  The  ebb  and  flow  of  the  tide,  the 
sand  blown  by  the  wind,  and  the  action  of  the  waves, 
which  often  undermine  one  part  and  elevate  another, 
may  cause  a  rock  to  present  the  diverse  stratification 
seen  in  Fig.  23. 

£..  lamination. — It  is  necessary  to  distinguish  be- 
tween stratification  and  lamination.  Separate  laminae, 
as  well  as  strata,  indicate  a  pause  in  the  process  of  depo- 
sition, whereby  the  sediment  had  time  partially  to  harden. 
The  former  denote  a  shorter  time,  so  that  the  laminae, 
in  general,  do  not  easily  separate  from  each  other.  In 
some  stones  it  requires  as  much  force  to  split  them 
along  the  planes  of  lamination  as  "across  the  grain." 
The  different  kinds  of  lamination  are  instructive,  since 
they  indicate  the  circumstances  under  which  the  rock 


80 


LITHOLOGICAL"~QEOL  0  G  T. 


was  formed.  Quiet  deposition  always  produced  parallel, 
slowly  rippling  waves,  curved,  and  pressure,  contorted, 
lamination. 

J.  J^autts*—  Vertical  cracks  or  seams  frequently  trav- 
erse the  rocks,  and  the  strata  on  one  side  slipping  away 
from  those  on  the  other,  the  layers  on  the  two  sides  do 
not  correspond.  During  the  unequal  movements  which 
have  produced  the  dislocation,  the  edges  have  often 
ground  together  so  as  to  become  polished  and  grooved. 
Fig.  24  represents  a  series  of  faults,  offsets,  as  they  are 
called,  in  the  iron  mine  at  Mt.  Pleasant,  N.  J. 

FIG.  24. 


Faults  (offsets)  in  Mt.  Pleasant  Iron  Mine,  Rockaway,  N.  J. 


6.  Jointed  Sh*ucture. — "When  these  vertical  cracks 
are  parallel  to  one  another,  and,  in  addition,  a  second 
system  crosses  the  first  at  right  angles,  the  rocks  are 
divided  into  regular  blocks,  forming  a  jointed  structure. 
On  Cayuga  Lake  the  rocky  bluffs  resemble  fortifications 


STRUCTURE     OF     THE     ROCKS. 


81 


with  towers  and  bastions.  Joints  in  the  rocks  are  almost 
invaluable  to  the  quarrymen.  It  would  be  a  most  dim- 
cult  task  indeed  to  quarry  a  rock  destitute  of  stratifica- 

FIG.  25. 


Jointed  Structure,  Cayuga  Lake. 

tion  and  joints.  These  seams  have  doubtless  been  pro* 
duced  partly  by  shrinkage  as  the  earth  has  cooled,  and 
partly  also  by  long-continued  lateral  pressure  consequent 
upon  movements  of  the  earth's  crust.  The  fact  that  the 
joints  of  any  region  are  ^arallel  to  one  another  indicates 
a  common  origin. 

7.  Folds. — Strata  are  often  so  folded  upon  one  an- 
other that  it  is  difficult  to  decide  upon  their  relative  age. 
Huge  mountains  consist  of  rocks  twisted  and  contorted 
as  if  they  had  been  "crumpled  up"  by  some  mighty 
hand.  Fig.  26  represents  a  section  of  slate  1000  feet 
long  and  300  feet  high,  taken  in  the  coast  ranges  of 
California.  After  these  were  deposited  as  sediment,  they 
were  crushed  together  and  bent  over  by  steady  lateral 


LITHOLOGICAL      GEOLOGY. 


pressure.*     "  How  prodigious  the  force  which  could  fold 
the  rocky  strata  of  a  mountain  as  one  would  the  leaves 


FIG.  26. 


FIG.  27. 


Flexures  in  Slate,  Coast  Range,  California. 

of  a  book/'  After  rocks  have  been  folded  in  this  man- 
ner, the  top  has  often  been  removed  by  denudation^ 
i.  e.9  the  action  of  water,  leaving  parallel  strata  standing 
on  edge,  the  older  or  lower  being  above  the  newer. 
Thus,  in  Fig.  27,  if  the 
fold  were  swept  off  down 
to  the  line  D  E,  there 
would  be  no  appearance  D 
of  anything  more  than  a 
mere  tilting  up  of  the  ABC  ABC 

A  Decapitated  Fold. 

strata;    yet   the   layer   A 

would  lie  above   C,  when   it  was   really  deposited   be- 
low it. 


*  Lyell  illustrates  the  effects  which  pressure  would  produce  on  flexible  strata 
by  laying  several  pieces  of  cloth  upon  one  another  in  a  pile,  and  then  placing  a 
book  on  top ;  apply  other  books  at  each  end  and  force  them  toward  each  other. 
The  folding  of  the  cloth  will  exactly  imitate  the  folding  seen  in  the  rock  strata. 

t  Near  Chambersburg,  Pa.,  there  is  a  fault  20  miles  in  length,  and  the  depth  of 
the  dislocation  is  20,000  feet,  and  yet  a  man  can  stand  with  one  foot  on  one  side 
of  this  fracture  and  the  other  foot  on  the  other  side.  What  has  become,  then,  of 
this  immense  mass  of  material  20,000  feet  in  height  It  must  have  been  swept 
into  the  Atlantic  by  the  denuding  flood.  If  this  had  not  been  done,  a  bold 
precipice  would  have  stood  there  nearly  four  miles  in  height  and  twenty 
miles  in  length.  Long  ages  must  have  been  required  for  water  to  effect  such  a 
denudation.  —Lesley, 


STRUCTURE     OF    THE    ROCKS.  83 

8.  Concretions  are  rounded  nodules  formed  by  the 
tendency  of  matter  to  collect  about  a  center.  They  are 
usually  flattened,  though  they  are  sometimes  quite  spher- 
ical. At  the  center  there  is  most  commonly  some  foreign 
object,  a  fossil,  shell,  twig,  or  the  like,  which  was  the 
nucleus  of  the  crystallization.  In  some  iron  mines  are 
found  balls  of  ore,  which,  from  their  peculiar  form, 
are  termed  "kidney  shaped."  Calcareous  concretions, 
washed  up  by  the  waves,  abound  along  the  shores  of 
Lake  Erie.  They  have  been  found  as  large  as  six  feet 
in  diameter.  They  sometimes  have  the  shape  of  large 
sea-turtles,  and  the  cracks  formed  by  shrinkage  often  re- 
sembling the  plates  of  the  shell,  they  are  considered  by 
the  neighboring  people  as  petrified  relics  of  that  animal. 
On  the  coast  of  Durham,  England,  the  magnesian  lime- 
stone forms  bold  cliffs,  which  look  as  if  made  up  of  irreg- 
ularly piled  cannon  balls.  When  the  internal  cracks 
formed  in  drying  have  become  filled  with  spar,  the  con- 
cretions are  termed  septaria  (septum,  a  division),  and, 

FIG.  28. 


Claystone,  Springfield,  Mass. 


when  cut  and  polished,  present  an  ornamental  appear- 
ance.    They  are  so  abundant  as  to  be  used  in  making  the 


84  L1TKOLOG1CAL     a  $  0  L  0  G  Y. 

famous  Eoman  cement.  In  beds  of  clay  containing  con- 
siderable carbonate  of  lime  are  found  peculiar  concretions 
called  claystones.  They  are  popularly  supposed  to  be 
worn  by  the  water.  They  often  assume  most  fantastic 
shapes,  resembling  familiar  objects,  such  as  a  hat,  bird, 
ring,  etc.  A  variety  of  limestone  composed  of  minute 
concretions,  often  as  small  as  a  grain  of  sand,  is  termed 
oolitic  (see  Fig.  7).  Along  the  limestone  bluifs  of  the  Mis- 
sissippi beautiful  "  geodes "  are  found.  Externally  they 
are  merely  rough  stones,  but  a  blow  of  the  hammer  re- 
veals the  interior  lined  with  delicate  quartz  crystals.* 
Fig.  29  represents  iron  nodules,  found  in  coal  mines, 

FIGS.  29-32 


r3 

Ironstone  Nodules,  showing  Varieties  of  Central  Nuclei. 

with  their  central  nuclei — No.  1,  a  fragment  of  a  plant ; 
2,  a  fish-tooth ;  3,  a  coprolite  (fossil  excrement) ;  and  4, 
a  septarium,  with  curious  partitions  of  white  carbonate  of 
lime,  giving  the  section  the  appearance  of  a  beetle;  from 
which  circumstance  such  nodules  are  known  in  some 
places  as  beetle  stones. 

*  "  Water  is  sometimes  found  in  the  geodee,  holding  the  silex  in  solution, 
and  making  with  it  a  milky  looking  mixture.  As  the  water  evaporates,  the 
silex  has  been  known  suddenly  to  form  into  delicate  crystals.  Such  geodes 
were  at  one  time  abundantly  found  on  Briar  Creek,  in  Scriven  or  Burke  County, 
Ga.,  in  a  rock  composed  of  hornstone  and  jasper;  the  milky  fluid  contained  in 
them  was  used  by  the  inhabitants  as  a  paint  or  whitewash." — Am.  Journal  of 
Science. 


STRUCTURE     OF    THE    ROCKS. 


85 


9.    Slate  Structure.  —  This  term  is  commonly  ap- 
plied to  any  rock  which  splits  into  thin  layers.    The  true 


FIG.  33- 


Section  exhibiting  Lines  of  Cleavage. 


slate,  however,  splits  in  layers  transverse,  often  at  right 
angles  to  the  strata.  Such  rocks  have  been  changed  from 
clay  shales  by  metamorphic  action,  in  which  process  they 
have  been  hardened  and  partially  crystallized,  while  at 
the  same  time  they  have  been  submitted  to  long-con- 
tinued lateral  pressure.  Prof.  Tyndall  has  shown  that 
even  soft  clay  will  in  this  manner  divide  into  thin 
laminae. 

(  2. )    UNSTRATIFIED    ROCKS. 

The  unstratified  rocks  are  found  as  shapeless  masses 
underlying,  overlying,  and  sometimes  penetrating  the 
stratified  rocks. 

/.  ^Definitions.—  In  Fig.  34,  C  is  an  underlying 
mass  of  granite,  e  is  a  stratum  forced  between  two 


FIG.  34. 


c  B  A 

strata  of  sedimentary  rocks,  d  is  an  overlying  mass,  and 


86 


LITHOLOGICAL     GEOLOGY. 


A  simply  a  mass  thrown  up  from  below,  and   disrupt- 
ing the  regular  stratified  rocks  above  it.     In   Fig.  35, 

FIG.  35. 


at  c  is  a  fault  in  the  rocks,  and  the  joint  at  that  point 
filled  with  igneous  rock  is  called  a  dike.  At  a  is  a  series 
of  veins  traversing  a  stratified  and  an  unstratified  rock. 

2.  Veins  are  fissures  in  the  rock  strata,  filled  with 
crystallized  mineral  matter,  such  as  fluor  spar,  quartz, 
etc.     They  are  of  all  sizes,  from  an  inch  to  many  feet 
in   thickness.     We   often   find   rocks   and  even  pebbles 
crowded  with  veins  sometimes  not  thicker  than  a  sheet 
of  paper  (see  Fig.  39). 

3.  1)ifces  are  wide  fissures  filled  with  igneous  rocks 
or  recent  lava.     They  are  generally   larger  than  veins, 
have  their  sides  more  nearly  parallel,  ramify  less  com- 
monly in  branching  veins,  and  contain  but  a  single  kind 
of  rock.     In  Fig.  36  is  a  representation  of  modern  dikes 
near  Mt.  Etna.     The  term  dike  means  a  wall.     It  is  de- 
rived from  the  fact  that  the  trap  is  generally  harder  than 
the  adjacent  rock,  and  hence  disintegrates  more  slowly 
when  exposed  to  the  elements.     The  dike  thus  projects 
above  the  surface  like  a  wall,  often  traversing  the  coun- 
try for  many  miles.    Hugh  Miller,  in  speaking  of  the 


STRUCTURE     OF    THE    ROCKS.  87 

FIG.  36. 


Modern  Dikes  near  Mt.  Etna. 


scenery  about  Edinburgh,  compares  the  denuding  influ- 
ences to  the  work  of  the  sculptor;  as  he  brings  out  his 

FIG.  37. 


Trap  Dike,  Lake  Superior. 


88 


L1TBOLO  QIC AL      GEOLOGY. 


FIG.  38 


figures  in  relief  by  cutting  away  about  them,  so  Time 
scoops  away  the  sand  rock  and  shale,  and  leaves  the  bold, 
rugged  features  of  the  trap  ridges. 
When  veins   cross  each    other,  it  is   easy  to   decide 

upon  their  relative 
age,  the  one  which 
is  separated  being 
necessarily  the  older. 
Thus  in  Fig.  38 
there  is  a  trap-dike 
protruding  through 
a  bed  of  gneiss,  and 
crossing  that  is  a 
vein  of  quartz,  a  b. 
Prof.  Hitchcock  de- 
scribes a  block  of  greenstone  which  exhibits  eleven  series 
of  veins. 


Dike. 

a  b.   A  Quartz  Vein  passing  through  a  Greenstone 
Dike  and  Layers  of  Gneiss. 


<£.  Origin  of  Veins  and  2>i£es.—Wl\en  the 
rocks  cooled  from  a  melted,  or  dried  from  a  moist  state, 
they  naturally  shrank  so  as  to  form  cracks  or  seam? 
of  varying  size.  In  different  ways  Nature  collected 
material  to  fasten  the  rocks  together  again.  Some  clefts 
were  filled  by  melted  rocks  injected  from  below,  and  then 
cooled.  This  is  known,  because  the  adjacent  rocks  are 
metamorphosed  by  contact  with  the  burning  mass,  and 
wear  a  different  look  from  the  rest,  while  the  mass  itself, 
by  its  crystallization,  shows  that  it  cooled  sooner  on  the 
outside  against  the  walls  than  at  the  center.  Dikes  pass- 
ing through  beds  of  chalk  in  the  county  of  Antrim,  in 
the  north  of  Ireland,  have  changed  the  chalk  to  mar- 
ble. Some  seams  were  filled  by  chemical  processes  with 


SVRVCTVRfi    OF   T&JS   ROCKS.  89 

matter  which  crystallized  out  from  the  adjacent  rocks, 
as,  for  example,  a  plaster  rock  dark  and  muddy  is  often 
found  crossed  with  layers  and  filaments  of  white;  trans- 
parent selenite  crystals,  which  have  doubtless  been  formed 
from  the  parent  stone.  The  larger  number,  however,  of 
these  rents  were  mended  with  rock  material  from  highly- 
heated  water  charged  with  mineral  matter.*  This  water 
filtering  through  the  finest  seams  of  the  rock  would  fill 
them  with  a  crystalline  paste.  We  often  see  this  process 

FIG.  39. 


Vein-form  Pebble  from  Drift,  Elmira. 


*  Large  rocks  are  sometimes  as  full  of  veins  as  your  hand  is,  and  of  veins 
nearly  as  fine  (only  a  rock-vein  does  not  mean  a  tube  but  a  crack).  These  clefts 
are  mended  usually  with  the  strongest  material  the  rock  can  find,  and  often 
literally  with  threads ;  for  the  gradually  opening  rent  seems  to  draw  the  sub- 
stance it  is  filled  with  into  fibers  which  cross  from  one  side  to  the  other,  so 
that  when  the  crystals  become  distinct,  the  fissure  has  often  the  look  of  a  rent 
brought  together  with  strong  cross  stitches.  When  all  has  been  fastened,  a  new 
change  of  temperature  may  occur,  and  the  rock  contract  again.  The  old  vein 
must  open  and  a  new  one  be  formed.  If  the  old  one  be  well  filled  the  cross 
stitches  will  be  too  strong  to  break,  so  that  it  can  only  give  away  at  the  sides 
and  thus  this  space  being  filled  afterward,  a  supplementary  vein  is  added.  In 
this  manner  three  or  four  parallel  veins  have  been  made.— Buskin. 


LITHOLOGICAL      GEOLOGY. 


FIG.  40. 


beautifully  illustrated 
in  an  opaque  uncrys- 
talline  rock,  and  in 
pebbles  threaded  with 
fine  crystalline  veins 
of  a  different  variety. 
(Fig.  39.)  Veins  are 
often  rich  in  metallic 
ores.  Sometimes  the 
metal  in  such  cases 
has  been  sublimed  by 
heat  below,  and  car- 
ried up  either  with 
steam  or  melted  mat- 
ter, and  deposited  in 
the  rock  fissures 
above.  In  the  figure 
is  shown  a  valuable 
vein  of  lead-ore  for- 
merly worked  at  Kos- 
sie,  N.  Y.  This  is 
the  simplest  form  of 
a  metallic  vein  (lode), 
as  it  is  a  mere  vertical 
sheet.  Like  most  me- 
tallic veins,  it  is  doubt- 
less an  aqueous  de- 
posit, the  material 
being  derived  from  the 
surrounding  rocks. 


Lead  Vein  01  Rossie,  N.  Y. 


ff  The  crust  of  our  earth  is  a  great  cemetery,  where  the  rock* 
are  tombstones  on  which  the  buried  dead  have  written  their 
own  epitaphs." — ACU.SSIZ. 


THE  history  of  the  formation  of  the  earth's  crust  is 
not  yet  fully  written.  In  its  investigation  many  diffi- 
culties are  met.  Strata  were  not  made  over  the  whole 
earth  at  the  same  time,  so  that  the  coatings  of  rock  are 
not  uniform.  Again,  some  are  found  in  one  section 
which  are  wanting  in  others,  and  the  same  strata  even 
are  composed  frequently  of  diverse  material  in  different 
parts  of  the  earth.  Thus,  the  chalk  formation  of  Eng- 
land is  represented  by  sandstone,  marl  and  limestone  in 
this  country,  though  all  belong  to  the  same  era.  It  is 
therefore  a  difficult  task  to  put  together  these  scat- 
tered fragments.  "The  world  is  to  the  geologist  a 
great  puzzle  box."  He  is  to  trace  the  resemblances 
and  learn  how  to  combine  all  the  widely  strewn  parts  of 
the  world's  history,  and  to  arrange  them  in  order  and 
symmetry.  Experience  alone  can  teach  him  accurately 
to  read  the  rocky  leaves  of  the  book  of  nature.  In 
this  work  the  fossils  are  his  chief  reliance.  They  have 
been  well  termed  the  "Medals  of  Creation,"  since  by 
their  means  the  geologist  identifies  different  strata,  and 


94  HISTORICAL     GEOLOGY. 

judges  of  the  successive  creations  of  animals  and  plants 
through  the  ages  of  the  past.  As  the  seals,  medals,  coins, 
etc.,  found  in  a  ruined  city  concerning  which  history  is 
silent,  declare  its  nationality,  so  the  organic  remains  of  a 
stratum  determine  its  geologic  period  and  characteristics. 
Each  epoch  recorded  in  its  rocks  and  fossils  the  history 
of  the  life  which  it  supported,  and  the  changes  through 
which  it  passed.*  Each  formation  possesses  its  peculiar 
fossils.  This  similarity  obtains  in  a  great  degree  over  the 
entire  world.  Thus,  the  identification  of  fossils  is  the 
identification  of  formations.  We  can  therefore  under- 
stand with  what  eagerness  these  are  gathered  and  pre- 
served. Fragments  which  the  ignorant  would  spurn 
from  his  feet  are  invested  with  as  high  an  interest  as  the 
obelisks  of  Egypt  or  the  sculptures  of  Nineveh.  The 
antiquarian  pores  over  those  with  intensest  enthusiasm, 
seeking  to  read  the  history  of  a  few  thousand  years.  The 
geologist  bends  with  equal  delight  over  the  forms  and 
impressions  of  the  rocks,  seeking  to  gather  information 
with  regard  to  a  past,  compared  to  the  duration  of  which 
the  chronology  of  man  is  but  as  the  moments  of  yester- 
day. The  print  of  a  leaf,  a  petrified  shell,  a  tooth,  the 
fragment  of  a  bone,  a  fish-scale  even,  may  serve  to  un- 
riddle the  most  puzzling  problem.  Eough  and  mutilated 


*  "  Nature  has  all  her  facts  stereotyped.  She  writes  her  events  often  upon  the 
most  fragile  plants  and  flowers,  on  the  very  winds  and  waters — all  the  most 
evanescent  and  changing  forms,  as  well  as  the  most  permanent.  Her  record  is 
as  enduring  as  the  phases  of  the  object  upon  which  she  writes,  and  sometimes, 
as  if  fearing  both  would  be  lost,  she  petrifies  the  whole,  and  leaves  it  thus  to 
endure  for  the  ages.  She  has  often  preserved  in  stone  the  history  of  her  frailest 
leaves,  her  most  ephemeral  and  minutest  insects  and  infusoria,  the  record  of  her 
ebbing  and  flowing  tides,  of  the  piles  of  dust  blown  together  by  her  winds,  the 
footprints  of  her  smallest  birds,  and  of  her  rain-drops  falling  upon  the  sand,"-~ 


HISTORICAL      GEOLOGY.  95 

though  the  fragments  may  be,  to  the  educated  eye  they 
embody  a  tale  as  legible  as  any  sculpture  or  hieroglyph- 
ics, and  far  more  comprehensive.  That  tiny  stem,  a 
mere  discoloration  on  the  rock,  once  floated  as  sea-weed 
in  the  waters ;  that  reed  once  luxuriated  in  a  primeval 
marsh;  that  delicate  rock  impression  was  a  fern  that 
once  waved  in  the  sunshine ;  and  that  simple  leaf,  now 
only  a  film  of  coal-like  matter,  sparkled  with  the  dew  of 
heaven  as  certainly  as  the  tender  herb  is  cherished  by  the 
dew  to-day,  or  existing  verdure  grows  to  beauty  in  the 
sunlight.  Every  trace,  then,  becomes  a  letter,  every 
fragment  a  word,  every  perfect  fossil  a  chapter  in  the 
world's  history.  Each  tells  of  races  that  lived,  multi- 
plied and  died,  of  lands  that  were  tenanted,  and  waters 
thronged  with  life, — so  oft  repeated,  again  and  again,  that 
the  mind,  at  first  excited  by  the  marvels,  at  last  grows 
weary  and  loses  itself  in  the  contemplation  of  the  works 
of  the  Infinite  Creator. 

There  are  no  sharply-drawn  lines  between  the  different 
ages.  They  fade  into  each  other  as  insensibly  as  the 
mountain  blends  with  the  plain.  Yet  each  has  a  promi- 
nent idea,  and  chronicles  a  grand  transition  in  the  world's 
history.*  Lesser  changes  are  denoted  by  Periods,  Epochs, 
and  Groups.  Some,  at  least,  of  the  revolutions  marking 
the  separate  ages  were  nearly  if  not  quite  universal. 
Those  denoting  the  other  divisions  were  more  local  in 
their  character.  The  periods  and  epochs  are  therefore 


*  The  land  now  lay  low  in  the  water,  and  anon  was  lifted  into  arid,  moun- 
tainous regions.  Consequent  upon  each  change  was  a  new  set  of  climatic  influ- 
ences, winds,  ocean  currents,  rains,  etc.,  each  necessarily  producing  its  impress 
on  the  vegetable  and  animal  life  of  the  period.  Thus  there  were  pauses,  as  it 
were,  in  the  deposition  of  sediment,  each  pause  making  a  break  in  the  strata. 


96  HISTORICAL     GEOGRAPHY. 

not  the  same  in  Europe  and  America.  They  vary  much 
in  the  formations  which  are  represented  even  on  the 
Atlantic  slope  and  in  the  Mississippi  valley. 

Geological  divisions. — The  history  of  the  earth's 
crust  is  divided  into  four  great  eras  or  times,  known 
as  the  Eozoic  (dawn  of  life),  the  PALEOZOIC  (ancient 
life),  the  MESOZOIC  (middle  life),  and  the  CE:N~OZOIC 
(recent  life).  These  names  indicate  the  successive  stages 
in  the  development  of  life  on  the  globe. 


I.     EOZOIC     TIME. 

AGE  OF  PROTOZOANS. 

II.     PALEOZOIC     TIME. 

1.  SILURIAN  AGE  (Age  of  Mollusks). 

2.  DEVONIAN  AGE  (Age  of  Fishes). 

3.  CARBONIFEROUS  AGE  (Age  of  Coal-Plants). 

III.  MESOZOIC     TIME. 

AGE  OF  REPTILES. 

IV.  CENOZOIC     TIME. 

AGE  OF  MAMMALS. 


The  table  on  page  97  contains  the  various  subdivisions 
now  generally  accepted,  the  lowest  in  order  of  time  being 
placed  at  the  bottom. 


PALEOZ 
TIME. 


as 


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TSDAM  PERIOD. 
JRONIAN  PERIOD. 

URENTIAN  PERIO 

ENTON  PERIOD. 

JDSON  PERIOD. 

AGARA  PERIOD. 

ZISKANY  PERIOD. 
>WER  HELDERBER 
LINA  PERIOD. 

^PER  HELDERBER 

\MILTON  PERIOD. 

LTSKILL  PERIOD. 
IEMUNG  PERIOD. 

BCARBONIFEROUS 

.RMIAN  PERIOD. 

LRBONIFEROUS  PE 

ETACEOUS  PERIO 
RASSIC  PERIOD. 
JASSIC  PERIOD. 

CRTIARY  PERIOD. 

p 

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ST-TERTIARY  PE 
Quaternary  Per 


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wl°  Sg-i 


98  HISTORICAL     GEOLOGY. 

The  ^Duration  of  Time  represented  by  these 
geological  periods  and  epochs  we  have  no  means  of  judg- 
ing. Estimating  the  past,  however,  by  the  present  rate 
of  change,  it  must  be  immense,  so  that  even  if  we  could 
express  it  in  centuries  and  years,  we  could  form  no  idea 
of  the  aggregate  any  more  than  we  can  comprehend  the 
distances  that  separate  our  earth  from  the  fixed  stars. 
This  idea  of  immense  duration  of  time  is  suggested  at 
the  first  examination  of  the  stratified  rocks.  All  that 
Geology  attempts,  at  present,  is  to  arrange  in  regular 
order  the  various  stages  of  progress  in  the  history  of 
the  earth's  crust,  leaving  it  for  the  future  to  decide 
upon  the  length  of  the  different  epochs.  As  yet  we 
know  only  that  "time  is  long"  and  hence  estimate  it 
by  ages,  eras,  and  periods,  rarely  venturing  more  than 
an  occasional  hint  at  their  relative  duration.  There  is 
an  eternity  of  time  as  well  as  of  space  in  which  God 
works  out  His  almighty  plan  of  creation.  Whatever 
may  have  been  our  preconceived  notions,  we  should 
come  to  the  study  of  Nature  with  a  reverent,  teach- 
able spirit,  seeking  to  learn  its  mysteries,  to  compre- 
hend its  plan,  and  to  understand  the  ways  of  Him 
who  created  all  things. 


OZOIC      §IME.* 

Probably  none  of  the  original  crust  of  the  earth  now 
survives.    If  any  still  exists,  it  perhaps  forms  the  foun- 


*  This  era  was,  until  lately,  universally  known  as  the  Azoic  (without  life). 
There  was  doubtless  such  a  period  when  the  heated  earth,  swept  by  a  boiling 
ocean,  was  destitute  of  inhabitants.  Recent  discoveries,  however,  seem  to 


EOZOIC     TIME.  99 

dation  rock,  *  and  is  buried  deep  beneath  later  deposits 
and  the  ruins  of  the  tremendous  changes  which   have 
since  occurred-!     The  oldest  rocks  now  known  upon  the 
surface  of  the  earth  probably  represent  Eozoic  Time. 
The  following  periods  are  recognized :  J 


K: 


T-,  ,  *..  Huronian  Period. 

Eozoic  TIME.  \ 

Laurentian  Period. 


Both  these  are  named  from  the  localities  where  they 
chiefly  occur,  viz.,  the  mountains  on  the  N.W.  of  the 
Eiver  St.  Lawrence,  and  on  the  north  of  Lake  Huron. 


indicate  that  the  lowest  of  the  so-called  Azoic  rocks  which  have  actually  been 
observed,  exhibit  proof  of  the  existence  of  life,  and  the  name  Eozoic  (dawn  of 
life)  has  therefore  been  substituted.  Dana  does  not  accept  this  conclusion, 
and,  in  the  revised  edition  of  his  Manual  of  Geology,  proposes  the  name 
Archaean  (beginning)  as  being  non-committal.  There  is  no  doubt  that  the 
Eozoic  was  preceded  by  an  Azoic  era,  but  it  yet  remains  for  the  rocks  of  either 
period  to  be  fully  identified. 

*  Winchell  suggests  that  likely  the  lowest  Azoic  rocks  in  the  earth's  pave- 
ment have  melted  off  as  the  isogeothermal  line  has  gradually  risen  through  the 
thickening  of  the  earth's  crust. 

t  In  the  Azoic  rocks  are  conglomerates  bearing  no  resemblance  to  the  beds 
in  which  they  are  found.  They  are  fragments  of  other  rocks,  other  continents 
perhaps,  broken  up  and  destroyed.  There  is,  then,  little  hope  of  our  discover- 
ing the  origin  of  life  on  the  globe,  since  this  page  of  the  genesis  of  the  facts  has 
been  torn.  For  some  years  geologists  loved  to  rest  their  eyes  in  this  long  night 
of  ages  upon  an  ideal  limit,  beyond  which  plants  and  animals  would  cease  to 
appear.  Now,  this  line  of  demarcation  between  the  rocks  which  are  without 
vestiges  of  organized  beings  and  those  which  contain  fossils  are  nearly  effaced 
among  the  surrounding  ruins.  On  the  horizon  of  the  primitive  world  we  see 
vaguely  indicated  a  series  of  other  worlds  which  have  altogether  disappeared ; 
perhaps  it  is  necessary  to  resign  ourselves  to  the  fact  that  the  dawn  of  life  is  lost 
In  this  silent  epoch  where  age  succeeds  age  till  they  are  clothed  in  the  garb  of 
eternity.  The  river  of  creation  is  like  the  River  Nile,  which,  as  Bossuet  says, 
hides  its  head— a  figure  of  speech  which  time  has  falsified ;  but  the  endless  spec- 
ulations opened  up  by  these  and  similar  considerations  led  Lyell  to  say:  "  Here 
I  am  almost  prepared  to  believe  in  the  ancient  existence  of  the  Atlantis  of 
Plato."— M.  Esquiros. 

$  T.  Sterry  Hunt  classifies  the  Eozoic  rocks  into  four  periods,  according  to 
their  lithological  peculiarities,  viz.,  Laurentian,  Huronian,  White  Mountain, 
and  Labrador. 


100  HISTORICAL     GEOLOGY. 

The  beds  of    Lauren tian  rocks  are   about  30,000  feet 
thick,  and  the  Huronian  from  10,000  to  20,000  feet. 

ZtOCalion. — On  our  continent  the  Eozoic  area  com- 
prises the  surface  rock  of  a  V-shaped  region  resting  on 

FIG.  41. 


The  Eozoic  Continent. 

the  great  lakes,  one  arm  reaching  N.W.  to  the  Arctic 
Ocean,  and  the  other  N.E.  to  Labrador;  in  addition, 
there  are  isolated  sections,  as  shown  in  the  map  (Fig.  41). 
These  constitute,  so  far  as  we  know,  the  most  ancient 
dry  land  of  America — the  Canada  area  representing  the 
Eozoic  continent,  and  the  other  portions  widely  scat- 


EOZOIC     TIME.  101 

tered  islands.  "Walking  along  the  summit  of  that 
region,"  says  Agassiz,  "  we  may  feel  that  we  are  treading 
upon  the  granite  ridge  that  first  divided  the  waters  into 
a  Northern  and  a  Southern  ocean ;  and,  if  our  imagi- 
nation carry  us  so  far,  we  can  look  down  to  its  base,  and 
fancy  how  the  sea  washed  against  this  earliest  shore  of  a 
lifeless  world."  * 

Kinds  of  3?oc%.—The  rocks  are  generally  crys- 
talline or  metamorphic,  as  granite,  gneiss,  marble,  quartz- 
ite,  limestone,  etc.  Beds  of  graphite,  porphyry,  soap- 
stone  and  slates,  also  occur.  All  were  doubtless  de- 
posited as  sedimentary  strata,  and  afterward  crystallized. 
The  Eozoic  was  emphatically  the  era  of  iron.  The  iron- 
ore  beds  of  the  Adirondacks  in  northern  New  York, 
the  Iron  Mountain  of  Missouri,  the  Marquette  mines 
of  Lake  Superior,  and  many  others,  date  from  this  time. 

Fossils. — Little  is  definitely  known  concerning  the 
life  of  this  era.  The  earliest  organisms  were  doubtless 
very  simple,  hence  their  traces  in  the  rocks  would  natu- 
rally be  exceedingly  obscure.  Fig.  42  represents  the 
appearance  of  a  bit  of  fossiliferous  marble  from  the  Lau- 
rentian  rocks.  The  dark  layers  are  composed  of  serpen- 
tine, and  the  white  of  limestone.  If  the  latter  be  removed 
by  an  acid,  the  serpentine  layers  and  granules  resemble 


*  "To  me  it  seems,  that  to  look  on  the  first  land  that  was  ever  lifted  above 
the  waste  of  waters,  to  follow  the  shore  where  the  earliest  animals  and  plants 
were  created  when  the  thought  of  God  first  expressed'  itself  in  organic  forms, 
to  hold  in  one's  hand  a  bit  of  stone  from  an  old  sea-beach,  hardened  into  rock 
thousands  of  centuries  ago,  and  studded  with  the  beings  that  once  crept  upon 
Its  surface  or  were  stranded  there  by  some  retreating  wave,  is  even  of  deeper 
interest  to  men  than  the  relics  of  their  own  race,  for  these  things  tell  more 
directly  of  the  thoughts  and  creative  acts  of  God." — Agassiz, 


10%  HISTORICAL     GEOLOGY. 

the  casts  of  Khizopods.*     To  this  Laurentian  fossil,  the 
relic  of  the  creature  that,  so  far  as  we  now  know,  first  in- 
habited the  earth,  the  name  of  Eozoon 
Canadense  (Canadian  dawn-animal)  has 
been  given. 

No  vegetable  remains  have  yet  been 
detected.  Still  the  presence  of  graphite, 
which  is  so  abundant  that  there  is  as 
much  carbon  in  the  Laurentian  rocks 
as  in  the  same  amount  of  the  carbon- 

Serpenune^Marble  of      iferoug)  fc  almost   positive  proof   of  their 

former  existence.  The  immense  de- 
posits of  iron-ore  are  also  suggestive  of  abundant  vege- 
tation at  the  time  of  their  formation. f  It  would  seem 
reasonable  to  suppose  that  vegetable  life  had  the  prece- 
dence, since  the  animal  kingdom  is  wholly  dependent  on 
the  vegetable  for  its  subsistence ;  and  thai  the  first  vege- 


*  These  animals  are  named  root-footed  because  of  their  root-like  feet— fleshy 
stems,  which  they  often  extemporize  upon  occasion.  (See  "  Fourteen  Weeks  in 
Zoology,"  p.  275.)  It  is  proper  to  say  that  many  celebrated  geologists,  such  as 
Morse,  Whitney,  Burbank  and  others,  still  refuse  to  accept  the  organic  character 
of  the  EozoOn.  Mr.  Hawes  has  recently  discovered  in  what  are  supposed  to  be 
Huronian  greenstones  of  New  Hampshire,  fossils  allied  to  the  Eozoon,  the 
infiltering  mineral  occupying  the  casts  of  the  animal  being  a  silicate.  Should, 
however,  the  EozoOn  be  rejected,  the  limestone  of  the  Eozoic  still  suggests, 
if  it  does  not  prove,  the  presence  of  animal  life. 

t  It  is  thought  by  many  chemists  that  all  iron-ores  are  of  marsh  origin.  The 
growth  of  the  so-called  bog-iron  is  as  follows  :  Iron  is  contained  in  the  soil  in 
slight  amounts,  as  a  ferric  oxide  or  common  iron-rust,  which  is  insoluble  in 
water.  But  if  there  is  vegetable  matter  present  in  the  water,  it  deoxidizes  the 
iron,  changing  it  to  the  soluble  ferrous  oxide.  On  exposure  to  the  atmosphere, 
the  iron  takes  up  the  rejected  oxygen  again  and  with  it  water  (see  "  Fourteen 
Weeks  in  Chemistry,"  p.  154),  becoming  ferric  hydrate.  This,  being  insoluble, 
is  deposited  on  the  bottom  of  the  pond.  One  can  discover  this  reddish-brown 
sediment  of  iron-rust  accumulating  in  any  swamp.  At  various  points  in  New 
England  and  elsewhere  bog-iron  was  formerly  collected  in  such  abundance  as  to 
be  used  for  manufacturing  purposes.  The  ore  gathered  so  rapidly  that  the 
ponds  were  dredged  every  few  years. 


EOZOIC     TIME.  103 

tation  consisted  of  land-plants,  since  the  earth  would  be 
cooled  sufficiently  to  admit  of  life  sooner  than  the  water; 
and,  moreover,  plants  can  exist  in  hotter  waters  than  is 
possible  for  animals. 


.  —  /.  Mountains.  —  Between  Canada  and 
New  York  runs  a  range  of  hills  called  the  Lauren  tian.* 
They  are  probably  the  oldest  mountains  upon  the  con- 

tinent. 

2  .  Upfiearals.  —  The  metamorphism  of  the  Eozoic 
rocks  was  closely  attended  by  extensive  upheavals,  which 
twisted  and  folded  them,  throughout  vast  areas,  into 
every  conceivable  form.  They  commonly  remain,  how- 
ever, in  regular  layers,  which  can  be  traced.  This  would 
indicate  a  uniform  force  acting  at  right  angles  to  the 
dip  of  the  beds.  These  movements  must  have  taken 
place  prior  to  the  Silurian  age,  since  the  Silurian  rocks 
rest  unconformably  upon  the  Eozoic,  as  is  shown  in  the 
accompanying  figure.  The  sedimentary  rocks  A,  lie  hori- 
zontally upon  tilted  gneiss,  C,  and  black  slate,  B.  The 


*  "  Their  low  stature,  as  compared  with  that  of  other  more  lofty  mountain 
ranges,  is  in  accordance  with  an  invariable  rule,  by  which  the  relative  age  of 
mountains  may  be  estimated.  (A  conclusion  first  suggested  by  Hall.  See  Intro- 
duction to  Vol.  Ill,  New  York  State  Reports.)  The  oldest  mountains  are  the 
lowest,  while  the  younger  and  more  recent  ones  tower  above  their  elders,  and 
are  usually  more  torn  and  dislocated  also.  This  is  easily  understood  when  we 
remember  that  all  mountains  and  mountain  chains  are  the  result  of  upheavals, 
and  that  the  violence  of  the  outbreak  must  have  been  in  proportion  to  the 
strength  of  the  resistance.  When  the  crust  of  the  earth  was  so  thin  that  the 
heated  masses  within  easily  broke  through  it,  they  were  not  thrown  to  so  great 
a  height,  and  formed  comparatively  low  elevations,  such  as  the  Canadian  hills 
or  the  mountains  of  Bretagne  and  Wales.  But  in  later  times,  when  young, 
vigorous  giants,  such  as  the  Alps,  the  Himalayas,  or  later  still,  the  Rocky 
Mountains,  forced  their  way  out  from  their  fiery  prison-house,  the  crust  of  the 
earth  was  much  thicker,  and  fearful  indeed  must  have  been  the  convulsions 
which  attended  their  exit."—  Geological  Sketches,  Agassiz. 


104  HISTORICAL     GEOLOGY. 

FIG.  43. 


Unconformity  of  the  Lower  Silurian  with  the  Gneiss  at  Montmorency  Falls. 

Eozoic  rocks  at  Montmorency  are  about  12,000  feet  in 
thickness.  Through  what  ages  must  those  vast  deposits 
have  slowly  gathered  in  the  primeval  ocean ! 

3.  The  Outlines  of  the  Continent.—™^  V- 

shaped  Eozoic  land  was  the  nucleus  around  which  the 
continent  grew.  Through  the  subsequent  ages  addi- 
tions were  made  to  this  germ  upon  the  southeast  and 


EOZOIC     TIME.  106 

southwest  sides.  Its  very  shape  was  thus  a  prophecy  of 
the  shape  of  North  America.  The  direction  of  the  two 
arms  was  parallel  to  that  of  the  Atlantic  and  Pacific 
oceans  (Fig.  41).  The  land  and  the  sea  have  from  the 
beginning  maintained  these  relative  positions.  In  addi- 
tion, the  location  of  the  scattered  areas  of  primeval  rocks 
singularly  indicated  the  great  mountain  ranges  yet  to 
be  elevated.  We  are  thus  led  to  believe  that  the  thought 
of  God,  as  ultimately  revealed  in  the  form  of  this  con- 
tinent, was  fairly  outlined  in  the  first  land  that  appeared. 
How  accurately  did  the  ancient  "backbones"  define 
the  present  contour  of  the  finished  continent!  The  St. 
Lawrence  flows  to  the  sea  through  a  valley  parallel  to 
the  Laurentian  ridge  ;  the  Mississippi  River  in  a  second 
valley  inclosed  between  the  Appalachian  and  the  Rocky 
Mountains;  the  Mackenzie  finds  its  way  to  the  Arctic 
sea  in  a  third  valley  between  the  Rocky  and  the  Lau- 
rentian mountains ;  while  Hudson's  Bay  is  snugly  locked 
in  the  arms  of  the  Laurentian  Mountains. 

£.  T?ie  Mosaic  Account  informs  us  that  on  the 
third  day  the  waters  were  gathered  into  one  place  and 
the  dry  land  appeared,  and  that  vegetation  was  brought 
forth  as  a  later  Creation  of  the  same  day.  The  geologic 
record  of  the  Eozoic  age  agrees  with  the  first  portion, 
and  upon  the  second  gives  as  yet  only  hints  of  possible 
discoveries.  The  direct  rays  of  the  sun  could  not  pene- 
trate the  thick  mists  which  then  enshrouded  the  warm, 
damp  earth;  and  hence,  although  the  sun  and  moon 
had  shone  from  the  beginning,  they  were  not  yet  set 
in  the  firmament  to  rule  the  day  and  the  night. 


106  HISTORICAL     GEOLOGY. 

Scenic  Description. — The  varying  theories,  and 
the  meagre  geological  records  of  the  Eozoic  Time,  give 
scanty  materials  for  sketching  the  scenery  of  that  first 
of  the  world's  great  aeons.  Nature  was  then  lavish 
of  time,*  spending  half  of  all  geologic  history  in  work- 
ing out  the  skeleton  of  a  continent  and  developing  an  era 
of  protozoans.  The  imagination  must  fill  out  the  picture 
from  a  few  outlines.  The  earth,  larger  than  now.  The 
waters,  protected  by  a  thin  crust,  still  simmering  with  the 
interior  heat.  The  air,  heavy  with  moisture  and  dense 
with  carbonic-acid  gas.  The  granite  rocks,  clothed  with 
lichens.  The  shores,  strewed  with  sea- weeds  and  diatoms ; 
and  the  ocean  bottom,  covered  here  and  there  with  masses 
of  Rhizopods  slowly  building  up  their  lime-reefs.f 


§ALEOZOIC     flME. 

f  3.  Carboniferous  Age. 
PALEOZOIC  TIME.  -3  2.  Devonian  Age. 
(  i.  Silurian  Age. 

The  Paleozoic  time  is  divided  into  three  ages  to  mark 
the  great  life-changes  which  occurred.  These  are  called 
the  Silurian  or  Age  of  mollusks,  the  Devonian  or  Age 
of  fishes,  and  the  Carboniferous  or  Age  of  coal-plants. 


*  Since  this  long  beginning,  Nature  seems  to  have  "been  more  chary  of 
the  diminishing  years.  Dana  reckons  the  relative  length  of  the  Paleozoic, 
Mesozoic,  and  Cenozoic  times  as  12,  3,  and  1,  respectively. 

t  Read  an  excellent  article  on  "  The  Earlier  Forms  of  Life,"  by  Prof.  C.  H. 
Hitchcock,  in  Popular  Science  Monthly,  January,  1877. 


PALEOZOIC     TIME.  107 

Though  unlike  in  marked  particulars,  they  are  yet  dis- 
tinguished by  certain  common  features  in  the  life  they 
supported,  while  they  are  all  very  dissimilar  to  any  later 
formations.  Neither  birds  nor  mammals  were  known, 
and  many  extensive  classes  of  animals  which  charac- 
terized these  ages  disappeared  with  them. 

I.    SILURIAN    AGE. 

Oriskany  Period. 

Lower  Helderberg  Period. 

SILURIAN   AGE.     I  "  ["  xr  ^  ^^ 

/A  ,,  ^    \        I  i.  Niagara  Period. 

(AGE  OF  MOLLUSKS,)       *.    . 

r  -  Hudson  Period. 

Trenton  Period. 
Potsdam  Period. 

This  first  grand  stage  in  the  progress  of  life  on  the 
globe  was  so  called  by  Murchison,  the  celebrated  English 
geologist,  who,  having  investigated  it  in  Wales,  named 
it  from  the  ancient  Silures,  a  tribe  of  Britons  formerly 
inhabiting  that  region.  The  subdivisions  of  the  age 
vary  greatly  in  different  portions  even  of  the  United 
States.  The  Silurian  and  Devonian  rocks  are  very  dis- 
tinctly developed  in  New  York,  and  the  epochs  estab- 
lished in  the  geologic  survey  of  that  State  are  therefore 
accepted,  f  Fig.  44  is  an  ideal  section  extending  from 

*  The  Lower  Silurian  is  known  by  many  of  the  most  distinguished  American 
geologists  as  the  CAMBRIAN.  It  was  so  styled  by  Sedgwick,  the  contemporary 
of  Murchison,  from  Cambria,  the  Latin  name  of  Wales,  where  the  rocks  are 
extensively  developed.  Dana,  however,  makes  the  Cambrian  only  a  period 
extending  through  the  Potsdam.  According  to  Hall,  Scdgwick's  original  desig- 
nation included  the  Caradoc  =  Hudson  River  group  of  the  New  York  Survey. 

t  This  system  has  been  established  by  the  genius  and  toil  of  James  Hall, 
LL.D.,  State  geologist,  and  that  of  his  indefatigable  assistants.  The  New  York, 
nomenclature  is  accepted  by  all  geologists  as  the  standard  for  comparison. 


108  HISTORICAL     GEOLOGY. 

the  Eozoic  rocks  in  the  northeastern  part  of  the  State 
to  the  carboniferous  in  the  southern.    It  will  be  seen 


FIG.  44. 


Ideal  Section  of  the  New  York  Formations  (Ball). 

that  the  different  epochs  succeed  one  another  regularly. 
The  dip  of  the  strata  is  by  no  means  as  uniform  as  is 
represented,  nor  is  there  any  attempt  to  indicate  their 
relative  thickness.  This  illustrates  on  a  grand  scale  the 
fact  stated  on  page  77  concerning  the  method  of  geologic 
study. 

We  shall  see  that,  with,  each  period,  a  narrow,  irregular 
'belt  was  added  to  the  Eozoic  area,  from  which,  as  a  germ, 
the  continent  grew  by  successive  additions. 

General  Characteristics.—^  is  probable  that  at 
this  early  day  the  Appalachians  on  the  east  and  the 
Eocky  Mountains  on  the  west  were  great  reefs,  lifted 
above  the  floor  of  the  sea,  thus  rendering  the  interior  of 
the  continent  an  open  sea,  protected  in  some  measure 
from  the  ocean.  At  the  bottom  of  this  shallow  basin, 
sandstone,  shale  and  limestone  were  formed.  The  kind 
of  rock  varied  in  different  sections  of  the  country  and 
periods  of  the  age,  according  to  the  peculiar  circum- 
stances which  influenced  the  deposit  of  sediment  at  any 
specified  place  or  time.  There  were  broad  areas  of  low 
jnud-flats  and  wave-washed  sand-beaches.  There  may 


POTSDAM    PERIOD.  109 

have  been  rivers  and  lakes  on  the  Eozoic  continent,  but  if 
so,  they  have  entirely  disappeared  in  the  wreck  of  subse- 
quent changes. 

The  land  was  rocky  and  barren,  while  the  waters 
swarmed  with  crustaceans  and  mollusks.*  The  pale  sun, 
struggling  to  penetrate  the  dense  atmosphere  of  a  yet 
heated  primitive  world,  for  the  first  time  yielded  a  dim 
imperfect  light. 


POTSDAM     PERIOD.f 

Z/ocalion. — This  period  is  named  from  Potsdam,  a 
town  in  northern  New  York,  where  the  rock  is  exposed 
in  the  quarries  to  a  thickness  of  seventy  feet.  The  for- 
mation is  well  developed  in  Pennsylvania,  and  can  be 
traced  westward  through  Michigan,  along  the  southern 
shore  of  Lake  Superior,  through  Wisconsin  and  Min- 
nesota to  the  Black  Hills  of  Dakota,  southward  along 
the  Appalachian  range  from  Vermont  to  Alabama,  and 
is  known  in  Texas. 

l£ind  of  ffiocfc. — The  rock  varies  much  throughout 
this  wide  extent.  At  Potsdam  it  is  a  coarse,  hard  sand- 
stone; at  Malone,  a  friable  one;  at  Keeseville,  a  quartzite; 
and  at  other  localities,  a  fine  white  sand,  fit  for  glass- 


*  Mollusks  are  soft -bodied  animals  usually  inhabiting  a  shell,  like  an  oyster. 
The  crustaceans  are  covered  with  shells,  like  the  crab,  but  are  articulated  or 
jointed  animals. 

t  Dana  locates  at  the  base  of  the  Lower  Silurian  (Cambrian  system)  the 
ACADIAN  EPOCH,  which  includes  the  beds  of  St.  John,  New  Brunswick,  and  of 
Newfoundland.  This  rock  occurs  as  a  slate  at  St.  John  and  in  New  Brunswick, 
but  a  compact  kind  of  wacke  or  quartzite  at  Braintree  near  Boston,  Mass. 
(HaU.)  It  is  characterized  by  a  large  Trilobite,  the  Paradoxides— a  genus 
anknown  afterward. 


110 


SILURIAN    AGE. 


making.  At  some  points  in  the  east  it  is  a  good  building- 
stone,  smooth  solid  masses  being  taken  out  thirty  feet 
square  and  two  feet  thick;  while  at  the  west  it  is  often 
so  friable  as  to  crumble  in  the  fingers.  The  colors  are 
brown,  yellowish,  etc.,  often  beautifully  mottled  with  red 
or  gray,  and  in  the  west  with  green.  In  many  localities 
it  is  worm-burrowed,*  ripple-marked,  mud-cracked,  and 
rain-pitted,  showing  the  mode  of  its  formation  on  a  low 
sand-beach  or  mud-flat.  The  upper  portion  of  this 
period,  known  as  the  Calciferous  Epoch,\  is  in  part  a 
magnesian  limestone,  so  that  some  layers  are  even  burned 
for  lime.  The  fissures  and  geodes  are  often  lined  with 
quartz  crystals  as  in  Herkimer  county,  N.  Y.  In  the 
Mississippi  valley  its  character  changes,  the  silica  de- 
creases, and  it  is  called  the  Lower  Magnesian  Limestone. 


FIG.  45. 


Fossils.  —  A  brachiopod,  the 
lingula  (little  tongue),  so  named 
from  its  peculiar  shape,  is  a  char- 
acteristic fossil.  In  form  and 
size  the  shell  is  similar  to  the 
finger-nail.  The  peculiarity  of 
this  mollusk  was  that  it  grew 
on  a  fleshy  stem  which  anchored 
it  to  the  rock.  Several  species 
of  the  lingula  still  exist  in  the 
Moluccas.  A  crustacean,  the  trilobite  (three-lobed),  is 

*  The  holes  burrowed  out  by  marine  worms  were  filled  with  sand,  which 
hardened  like  the  rock  itself,  and,  when  the  rock  is  broken,  forms  regular  casts 
of  the  worm  -burrow. 

t  Logan  groups  the  Calciferous  Epoch,  the  Leyis  shales  and  sandstones  so 
abundant  near  Quebec,  and  the  Chazy  limestone  (p.  115),  into  a  new  period,  the 
CANADIAN.  It  is  probably  the  equivalent  of  a  part  of  Emmons's  Taconic 
system,  which  occurs  as  a  slate  rock  in  New  York  east  of  the  Hudson,  as  at  the 
outcrop  near  Poughkeepsie. 


antiqua. 


POTSDAM    PERIOD. 


Ill 


FIG.  46. 


the  most  conspicuous  fossil.  This  family  was  promi- 
nent in  the  early  creations,  but  disappeared  in  the 
Carboniferous  Age.  It  is  perfectly 
preserved,  and  the  various  stages 
of  growth,  from  the  egg  to  the 
adult,  have  been  more  accurately 
traced  than  even  those  of  the 
crab,  a  living  crustacean.  It  was 
of  wonderful  variety,  more  than 
400  species  having  been  discov- 
ered. It  had  an  oval  figure,  and 
was  from  %  of  an  inch  to  20  inches 
in  length.  The  body,  divided  into 
three  lobes,*  was  covered  with  a 
jointed  crust  which  folded  over  as  in  the  tail  of  a 
lobster.  Some  species  could  roll  themselves  up  into  a 
ball,  and  thus  present  a  hard  armor  in  every  direction. 
The  head  was  protected  by  a  buckler  of  a  crescent  form. 
The  eyes  were  conical  shaped,  and  each  one  was  com- 
posed of  many  separate  facets  or  lenses,  f  by  means  of 
which  the  animal  could  see  in  every  direction  at  once. 

The  inner  side  of  each  eye  being  of  no  practical  value, 
Nature,  on  her  principle  of  economy,  placed  no  lenses 
there.  The  trilobite  is  supposed  to  have  gathered  in 
shoals  in  the  shallow  water,  swimming  slowly  on  its  back 
by  means  of  membranous  appendages  now  lost. 


A  Trilobite  (Dicellocepha- 
lus  Minnesotensis.) 


*  The  head-shield  is  named  the  bucJder,  and  the  tail-shield,  the  pygidium. 
The  former  is  divided  longitudinally  into  the  glabella  or  middle  part,  and  the 
two  cheek  or  side  portions. 

t  Walcott  gives  the  number  in  a  specimen  of  Batnyurus  as  4,720,  and  in 
another  of  Asaphus,  7,536.  A  beetle  (genus  Mordella)  of  the  present  time  has 
25,008  of  these  facets  ;  a  butterfly  (genus  Papilio)  has  17,355  ;  a  house-fly,  4,000, 
and  an  ant.  50. 


112 


SILURIAN    A  GU. 


1,  2.    Eyes  of  Trilobites.    3.  Enlarged  Lens. 


*— /.  The  Atmosphere '.—The  eyes  of 
the  trilobite  would  have  been  useless  unless  the  atmos- 
phere had  been  clear  enough  to  permit  sufficient  sunlight 
to  reach  the  earth  to  render  objects  visible  in  some  de- 
gree. God  makes  all  things  for  a  purpose;  hence  we 
conclude  that  at  this  early  period  the  sun  had  pierced 
the  clouds,  and  the  air  was  being  purified. 

2.  fiarty  Silurian  Beach.—  Where  the  Pots- 
dam rock  lies  on  the  surface,  we  are  assured  that  that 
locality  was  raised  above  the  sea  at  or  near  the  close  of 
this  period  (unless  uncovered  by  subsequent  denudation), 
else  it  would  have  been  concealed  by  the  sediment  of  the 
succeeding  one.  The  narrow  zone  of  the  Potsdam  rock 
along  the  borders  of  the  Eozoic  area,  was  doubtless  the 
beach  of  the  early  Silurian  sea. 

3 '.  Ztife.-r- The  organic  remains  found  in  this  period 
are  principally  crustaceans  (Hall),  though  the  Protozoans, 
Badiates,*  Mollusks,  and  Articulates  are  represented 
among  animals,  and  the  sea-weeds  among  plants.  The 


*  For  the  sake  of  simplicity  the  two  sub-kingdoms,  Echinodermata  and 
Ccelenterata  are  here  combined  in  the  name  Radiates  (see  Zoology,  p.  13). 
They  are  BO  called  because  they  have  a  radiated  structure,  as  the  star-fish. 


POTSDAM    PERIOD.  118 

trilobite  was  the  highest  type.  All  the  sub-kingdoms  of 
invertebrates  were  thus  represented  ;  but  vertebrates  had 
not  yet  appeared.  No  signs  of  land  vegetation  have  been 
found.  The  dry  Eozoic  hills  may  have  been  covered  with 
lichens,  but  they  bore  no  moss  or  grass,  the  sea  contained 
no  fish,  and  the  air  no  bird. 

^.  Climate.  —  No  difference  is  seen  in  the  life  of 
different  latitudes;  hence  it  is  thought  that  there  was  a 
uniformity  of  temperature  existing  over  the  earth,  and 
that  the  diversity  of  zone  and  climate  had  not  yet  been 
established.  Various  reasons  have  been  assigned  for  this, 
among  which  are  —  (1)  the  greater  heat  from  the  inte- 
rior on  account  of  the  thinness  of  the  crust,  (2)  the 
dense  atmosphere  which  retained  the  sun's  heat  more 
fully,  (3)  the  great  expanse  of  the  ocean  which  tended  to 
equalize  the  temperature,  and  (4)  the  greater  size  and 
heat  of  the  sun  in  that  era,  according  to  the  nebular 
hypothesis. 


5.  Changes  in  the  Sea,  Z,ife,  and 

Shales  were  produced  in  the  muddy  water,  and  lime- 
stones in  the  shallow,  clearer  sea  —  since  the  coral  animal 
thrives  best  in  pure  water  less  than  a  hundred  feet  deep. 
The  crust  of  the  still  unsteady  earth,  as  it  rose  and 
fell,  shallowing  or  deepening  the  waters,  rendering  them 
muddier  or  purer,  varied  the  character  of  the  life  sup- 
ported and  the  rock  formed. 

6.  £afce  Stiperior.—Vo\e,%mc  convulsions  in  that 
region  having  tilted  the  rocks,  a  depression  of  the  crust 
was  produced,  thus  forming  the  bed  of  Lake  Superior. 


114  SILURIAN    AGE. 

In  this  connection  there  were  igneous  ejections,  making 
trap-rocks  and  dikes.  The  fissures  were  also  filled  with 
native  copper  and  silver,  among  the  richest  deposits  in 
the  world.  The  sandstone  has  since  been  worn  into 
grotesque  and  curious  forms  as  seen  in  the  famous 
Sculptured  and  Pillared  Eocks.  * 

7.  2 'he  Mosaic  Account  tells  us  that  the  sun  and 

FIG.  48. 


Sculptured  Rocks,  Lake  Superior.    "  Inverted  Volcano.' 


*  These  strata  form  a  wall  50  to  100  feet  high,  and  line  the  shore  for  a  distance 
of  five  miles.  Their  marked  hues  and  fantastic  shapes  excite  the  imagination 
of  every  beholder.  Here  is  "  Miner's  Castle,"  with  its  turrets  and  bastions ; 
there  "  Sail  Rock,"  a  ship  with  sails  full  spread ;  and  yonder  "  The  Amphi- 
theatre," with  its  symmetrical  curves.  A  closer  inspection  only  reveals  more 
curious  details  and  resemblances.  For  a  very  interesting  account  of  these 
rocks  see  Harpers'  Magazine,  Vol.  XXXIV,  p.  681, 


T&ENTON    PERIOD.  115 

moon  were  created  on  the  fourth  day.  Geology  shows 
us  that  the  distinctive  feature  of  the  early  Silurian 
Age  was  the  partial  clearing  of  the  sky  after  the  murky 
clouds  of  the  Eozoic.  The  first  glimpse  of  the  sun  would 
have  seemed  to  an  observer  as  a  new  creation,  and,  in 
popular  language,  it  is  thus  described  in  Genesis,  We 
also  read  that  on  the  fifth  day  the  waters  brought  forth 
abundantly  the  moving  creature  that  hath  life.  We  shall 
see  how  perfectly  the  swarming  seas  of  the  Silurian  and 
Devonian  Ages  justify  this  description. 

TRENTON     PERIOD. 

.Location. — The  Trenton  formation  extends  along 
the  great  Appalachian  chain  of  mountains  on  the  east, 
thence  outcrops  at  various  points  westward  to  the  Missis- 
sippi River,  and  beyond  the  Rocky  Mountains.  It  is 
more  widely  distributed  than  any  similar  deposit. 

IC'inds  of  ffiocfc. — This  was  the  first  great  limestone 
period  of  the  continent.  In  New  York  there  are  four 
epochs— (1)  the  Chazy  limestone,*  (Shaz-ee),  named  from 
a  locality  near  Lake  Champlain,  which  is  the  passage  rock 
from  the  Calciferous  sandstone ;  (2)  the  Bird's  Eye  lime- 
stone, a  dove-colored  rock  containing  white  crystalline 
points  scattered  through  it;  (3)  the  Black  River  lime- 
stone, a  black,  hard-grained  marble, f  named  from  the  river 

*  In  Wisconsin,  Iowa,  Minnesota,  and  Illinois,  the  equivalent  of  the  Chazy 
if*  the  St.  Peter's  sandstone, — a  soft,  white,  incoherent  rock,  composed  of  grains 
of  quartz  that  crumble  easily  under  the  hammer,  though  in  some  localities  it 
is  hardened  by  a  calcareous  cement.  It  is  used  in  Chicago  for  glass-making. 
Like  the  Lower  Magnesian  Limestone,  it  is  destitute  of  fossils.—  Whitney. 

t  At  Watertown.  N.  Y.,  it  is  lumpy,  and  breaks  into  rhomboidal  fragments, 
while  the  Bird's  Eye  has  a  conchoidal  fracture.  The  river  is  said  by  some  to 
take  its  name  from  the  dark  color  of  the  rocks  over  which  it  flows. 


116 


S1L  URIAN    A  GE. 


of  that  name,  east  of  Lake  Ontario ;  (4)  the  Trenton  lime- 
stone* a  hard,  compact  rock,  black  in  the  lower  beds  and 
gray  in  the  upper,  so  called  from  the  well-known  gorge 
at  Trenton  Falls.  In  Wisconsin,  Iowa,  etc.,  the  Galena 
limestone  is  an  upper  member  of  the  group  not  known 
at  the  east.  It  is  the  great  lead  and  zinc  bearing  rock 
of  a  region  embracing  about  .3,000  square  miles.  The 
streams  have  cut  deeply  down  into  this  formation,  so 
that  they  are  bordered  by  precipitous  bluffs  crowned 
by  perpendicular  ledges,  having  frequently  a  castellated 
appearance  like  the  walls  of  some  half-ruined  city,  while 

FIG.  49. 


Maclurea  Magna. 


*  The  massive  pillars  of  the  court-house  at  St.  Louis  are  from  the  Trenton 
limestone  quarries  of  Sulphur  Spring.  The  crest  of  the  Falls  of  St.  Anthony  is 
of  Trenton  limestone.  The  beautifully  variegated  marbles  of  Tennessee  are 
also  of  this  period. 


TRENTON    PERIOD. 


117 


isolated  masses  sometimes  rise  abruptly  from  the  valleys 
like  lofty  watch-towers. 

FIG.  50. 


FIG.  51. 


Bird's  Eye  Fucoid  (Phytopsis  tubulosum). 

Fossils. — A  peculiar  coiled  shell  (Fig.  49)  is  abun- 
dant in  the  Chazy.*     Fig.  50  represents  a  characteristic 

marine  plant  found  in  the 
Bird's  Eye  limestone.  The 
ends  of  the  stems  give  the 
rock  the  dotted  appearance 
from  which  it  takes  its 
name.  Fig.  51  is  a  coral 
common  in  the  Black  Kiver 
limestone.  It  has  been 
found  in  masses  of  a  ton's 
weight.  The  Trenton  lime^ 


Black  River  Coral  (Columnaria 
alveolata). 


*  Like  all  Gasteropods  (see  Zoology,  p.  244),  the  common  snail  for  example, 
It  moved  upon  a  fleshy  disk  or  foot  heneath  the  body.  The  layers  of  Chazy 
limestone,  when  worked  as  a  marble,  often  show  upon  a  dark  gray  surface  the 
white  spirals  of  this  shell. 


118  SILURIAN    AGE. 

stone  abounds  in  organic  remains.  Corals,  crinoids,  and 
shells  are  crowded  together  in  the  greatest  profusion. 
Thin,  semi-transparent  slices,  apparently  devoid  of  fossils, 
under  the  microscope  reveal  their  animal  origin. 

Brachiopods  *  occur  in  wonderful  variety.  Trilobites, 
•the  highest  type  of  the  Potsdam,  appear  of  a  dozen 
species,  varying  in  size  from  that  of  a  finger-nail  to  a 
foot  in  length.  They,  however,  yield  in  abundance, 
activity  and  power  to  the  cephalopods.f  A  family  of 
these,  the  Orthoceratite  (straight-horn),  distinguishes  the 
entire  period.  It  had  a  long  straight  shell,  divided  into 
sometimes  as  many  as  seventy  chambers.  These  were 
formed  to  accommodate  the  growth  of  the  animal.  As 
it  increased  in  size,  it  moved  forward  in  its  room,  and 
extending  its  shell  at  the  larger  end,  partitioned  off  its 
new  quarters  from  the  rest  by  a  shelly  wall.  Thus,  in 
time,  a  long  series  of  chambers  was  made,  each  larger 
than  its  predecessor. J  They  were  connected,  however, 

*  The  Brachiopods  (arm-footed)  are  bivalves  having  arms  by  which  they  stir 
the  water,  and  thus  bring  their  food  within  their  reach.  The  two  parts  of  the 
shell  are  unequal ;  the  larger  is  called  the  ventral  and  the  smaller  the  dorsal 
valve.  Each  valve  is,  however,  equal  sided,  so  that  if  a  line  be  dropped  from 
the  beak  to  the  opposite  side,  it  will  divide  the  valve  into  equal  parts. 

|  The  Cephalopod  (head-footed)  is  also  a  Mollusk,  something  like  the  Cuttle- 
fish of  to-day  (see  Zoology,  p.  243),  having  arms  arranged  around  the  head. 
%  "  Year  after  year  beheld  the  silent  toil 
That  spread  his  lustrous  coil ; 
Still  as  the  spiral  grew, 
He  left  the  past  year's  dwelling  for  the  new. 
Stole  with  soft  step  its  shining  archway  through, 

Built  up  its  idle  door, 

Stretched  in  his  last-found  home,  and  knew  the  old  no  more. 
•*  Thanks  for  the  heavenly  message  brought  by  thee, 
Child  of  the  wandering  sea, 
Cast  from  her  lap  forlorn. 
Cast  from  thy  dead  lips,  a  clearer  note  is  bora 
Than  ever  Triton  blew  from  wreathed  horn  ; 

While  on  my  ear  it  rings, 
Through  the  deep  caves  of  thought,  I  hear  a  voice  that  sings: 


TRILOBITES  OF  TRENTON    PERIOD. 


Orthoceras  multfcameratum  (Black  River 


SILURIAN    AGE. 

by  a  membranous  tube  ("  siphuncle  "),  which  passed  from 
the  animal  in  the  newest  and  largest  chamber  at  one 
end  to  the  oldest  and  smallest  room  at  the  other.  These 
empty  chambers  are  thought  to  have  acted  as  a  buoy  to 
float  the  heavy  animal.  Some  of  the  fossil  orthoceratites 
are  not  larger  than  a  lead  pencil,  while  others  are  a  foot 
thick  and  thirty  feet  in  length.  They  had  many  mus- 
cular arms,  with  which  they  seized  and  strangled  their 
prey  in  their  powerful  grasp.  They  were  doubtless  the 
sea-rovers  of  the  Lower  Silurian  Ocean. 

H  U  DSON     PERIO  D. 

ZfOCation .  — This  formation  is  exposed  to  view  along 
the  Hudson  and  Mohawk  rivers,  on  7  '-.?  Michigan  aad 
Green  Bay,  through  the  Mississippi  va.  aixd  ^-ng  the 
Appalachian  range  to  Alabama. 

J&nds  of  ffiocfc.—Io.  New  York  there  are  three 
epochs — 

(1)  The  Utica  slate,  a  fissile,  black  stone,  the  surface 
rock  of  the  Mohawk  valley;  (2)  the  Herkimer  shales,  and 
(3)  the  Loraine  shales,  and  the  Salmon  River  shales  and 
sandstones.* 

"  '  Build  thee  more  stately  mansions,  oh,  my  soul, 
As  the  swift  seasons  roll ! 
Leave  thy  low-vaulted  past ! 
Let  each  new  temple,  nobler  than  the  last, 
Shut  thee  from  heaven  with  a  dome  more  vast 

Till  thou  at  length  art  free  ; 

Leaving  thine  outgrown  shell  by  life's  unresting  sea.' " 

*  A  fourth  may  hereafter  be  recognized  as  terminating  the  period ;  viz.,  the 
Gray  sandstones  of  Oswego  county,  which  may  be  the  equivalent  of  the  Sha- 
wangunk  Grit.  In  the  Hudson  valley,  the  New  York  geologists  are  not  able 
clearly  to  distinguish  these  members,  owing  to  the  contortion  of  the  strata. 
At  some  points  the  Utica  slate  appears  on  the  surface,  owing  to  folding  of  th« 
beds  (Hall). 


HUDSON    PERIOD.  121 

This  period  includes  an  enormous  series  of  shalesa 
slate  and  sandstone,  reaching  a  thickness  of  perhaps 
1,000  feet.  The  color  is  dark  and  bitumen  is  often 
present  so  as  to  afford  a  black  pigment.  There  are  thin 
seams  of  a  shiny  slate  which  have  many  times  tantalized 
those  ignorant  of  geology  with  unfounded  hopes  of  the 
discovery  of  profitable  beds  of  coal. 

At  the  west  the  rock  becomes  a  soft  calcareous  shale 
interlaminated  with  limestone.  The  group  is  there 
known  as  the  CINCINNATI  PERIOD. 

Fossils. — In  the  limestone  regions  corals,  shells,  tri- 
lobites,  etc.,  are  abundant  as  in  the  Trenton  Period.  In 
the  shales,  however,  they  are  sparingly  distributed,  being 
mostly  those  which  flourish  in  muddy  waters.  The 
graptolites  (rock-writing)  of  the  kingdom  of  Radiates 
are  striking  fossils  (see  Fig.  53).  They  are  found  in  the 

FIG.  53. 


A.  Graptolite   with   Eight   Arms  (Graptolithus  octobrachiatus),  Quebec  Group. 

(Hall.) 

Potsdam,  but  become  very  plentiful  in  the  Hudson 
Period.  They  are  merely  a  delicate,  plume-like  tracery 
upon  the  rock.  They  have  therefore  been  poetically 


styled  sea-pens.  They  delighted  in  foul,  as  the  corals  in 
clear  water,  and  must  have  thickly  covered  the  muddy 
bottom  of  the  shallow  sea  with  their  fragile,  mossy 
branches.  They  are  commonly  found  in  scattered  frag- 
ments, the  arms  only  of  the  entire  animal  as  seen  in 
Fig.  53. 


Changes.—  Life  and  death 
were  coeval  from  the  first  —  one  species  giving  place  to 
another,  most  commonly  at  the  close  of  a  period,  but 
frequently  within  its  duration.  Some  catastrophe  oc- 
curred, for  example,  at  the  close  of  the  Chazy  Epoch 
which  destroyed  nearly  all  the  species  then  existing,  and 
the  Trenton  Epoch  was  therefore  characterized  by  new 
species.  It  was  still,  however,  the  reign  of  mollusks, 
since  that  subkingdom  was  exhibited  in  its  various 
classes,  while  the  articulates  had  not  progressed  above 
the  crustaceans  and  worms,  and  no  vertebrates  have  yet 
been  discovered.  Another  marked  change  took  place  at 
the  close  of  the  Lower  Silurian.  The  Green  Mountains 
were  upturned  and  metamorphosed,  thus  closing  the 
making  of  rocks  in  that  region,*  while  a  vast  section 
extending  from  Lake  Erie  to  Tennessee  was  raised  above 
the  ocean  so  as  to  form  a  great  island  in  the  Upper 
Silurian  Sea.  The  land,  so  far  as  geology  teaches, 
remained  leafless  and  lifeless  as  at  the  beginning.  The 
sea,  however,  in  its  shallower  places,  resembled  a  flower- 
garden,  with  its  abundant  corals. 


*  According  to  Hall,  however,  there  are  Devonian  limestones  at  Lake  Mem- 
phremagog  and  at  Bernardstown  in  Massachusetts,  and  Lower  Helderberg  in 
Maine. 


NIAGARA     PERIOD. 

2.  Geograpfi/y . — Lake  Champlain  probably  dates 
from  this  time.  The  continent  was  steadily  pushing  its 
way  southward  and  had  reached  the  central  part  of  New 
York.  'Western  New  England  had  emerged  from  the 
sea,  while  the  then  low,  narrow  Kocky  Mountains  repre- 
sented the  western  part  of  the  continent. 


NIAGARA     PERIOD. 

.  — This  is  a  continental  formation  like  the 
Trenton.  It  is  found  in  Canada,  and  extends  south 
through  the  Appalachian  region,  and  west  through  the 
M-ississippi  valley.  It  takes  its  name  from  the  fact  that 
the  great  cataract  of  Niagara  pours  over  a  rocky  wall 
of  this  period.  The  peculiar  form  of  the  fall  is  owing 
to  the  fact  that  the  soft  shale  below  wears  away  more 
rapidly  than  the  hard  rock  above,  thus  leaving  a  cavern 
behind  the  falling  sheet. 

J£inds  of  ffiocfc. — In  New  York  there  are  four 
epochs.  (1.)  The  Oneida  Conglomerate,*  called  from  a 
county  of  that  name  in  central  New  York,  is  a  gritty, 
hard  conglomerate,  so  rough  as  to  form  millstones. 
From  its  abundance  in  the  Shawangunk  Mountains  it 
is  locally  known  as  the  Shawangunk  grit.  (2.)  The 
Medina  sandstone,  named  from  the  locality  in  western 
New  York  where  the  rock  is  extensively  quarried  for 
building  purposes,  is  a  thickly  laminated  sandstone,  of 
red,  gray,  and  beautifully  mottled  colors.  (3.)  The  Clin- 


*  Hall  inclines  to  refer  this  conglomerate  to  the  Hudson  Period  as  a  fourth 
member.    (See  note  p.  120.)    It  is  clearly  a  passage  rock. 


1%4  SILURIAN    AGE. 

ton  Group,  so  called  from  a  village  in  central  New  York, 
is  generally  a  shale  or  sandstone,*  and  always  contains 
beds  of  limestone.  (4.)  The  Niagara  proper  consists  of 
a  shale  and  a  limestone  of  a  light  gray  or  cream  color  and 
of  an  enduring  hardness,  but  yet  soft  enough  to  be  easily 
wrought  in  any  desired  form.  The  so-called  "Athens 
marble  "  of  Illinois,  is  almost  a  pure  dolomite.  Around 
Chicago  the  stone  is  often  saturated  with  mineral  oil, 
At  Lockport,  New  York,  dog-tooth  and  pearl-spar,  also 
gypsum  and  other  minerals,  are  found  in  beautiful  crys- 
tals lining  the  cavities  in  the  rock.  At  the  west  the 
Niagara  limestone  stands  in  bold  bluffs  along  the  rivei 
banks.  It  contains  nodules  of  hornstone  ("  chert  "),  often 
arranged  in  layers  parallel  to  the  strata.  The  Niagara 
rock  is  frequently  found  capping  small  hills  or  knobs,  and 
has  hence  received  the  name  "  Mound  limestone."t 


lK  the  Clinton  beds  a  brachiopod  (the 
pentamerus,  five-parted)  is  very  abundant.  Sea-weeds 
(fucoids)  cover  the  Medina  sandstone  in  many  places. 
with  their  interlacing  stems,  curiously  wrought,  like  the 
intricate  carving  of  some  old  Gothic  cornice.  The 
Niagara  rocks  abound  in  corals,  crinoids,  shells,  etc. 
They  are  doubtless  the  remains  of  old  coral  reefs. 


*  In  Michigan  and  some  of  the  western  States  it  assumes  still  more  of  a  lime 
stone  character,  and  in  New  York,  Ohio,  and  Wisconsin,  has  beds  of  o61itic  iron 
ore  of  great  value.  In  Tennessee  it  is  called  u  dye-stone,"  being  extensively 
used  for  dyeing  cloth. 

t  The  Blue  Mounds,  Platte  Mounds,  Sinsinnewa  Mound,  in  Wisconsin; 
Sberald's,  in  Iowa ;  Scales's,  Charles's,  Waddell's,  Pilot's  Knob,  etc.,  in  Illinois  ; 
are  striking  examples  of  this  peculiarity,  since  they  form  conspicuous  landmarks 
in  the  scenery  of  those  States.  These  outliers  of  the  Niagara  limestone  assume 
a  great  variety  of  forms,  but  are  always  graceful  in  their  outlines,  and,  as  they 
are  generally  covered  with  forest  trees,  present  a  striking  contrast  to  the  rocky 
bluffs  of  the  Galena  limestone. 


NIAGARA      PERIOD.  125 

The  crinoids  appeared  in  preceding  periods,  but  now 
become  \*ery  plentiful.    They  grew  on  a  stem,  and  had 

FIG.  55. 


Medina  Fucoid  (Arthrophycus  Harlani).— (Hall.) 

somewhat  the  form  of  a  lily,  hence  have  received  the 
name  of  "stone  lilies."  Their  cup-shaped  body  sent  out, 
star-like,  five  or  more  arms ;  these  branched  sometimes 
into  as  many  as  a  thousand,  each  composed  of  a  hundred 
little  bones,  firmly  and  exquisitely  jointed  together.  The 
stalk  was  also  jointed,  like  the  vertebras  of  the  spine,  and 
was  curiously  grooved  and  ornamented  on  the  surface. 
The  arms  were  adapted  to  be  spread  out,  and  lined  with 
tentacles  to  seize  and  draw  into  the  centre  shoals  of 
animals,  the  food  of  the  crinoid.  Their  forms  were  of 
varied  patterns,  and  their  markings  exquisitely  beautiful. 
(See  Zoology,  pp.  263,  264.)  In  many  places  the  rock  is 
a  confused  mass  of  crinoidal  stems  (Figs.  58  and  75), 
which,  when  polished,  present  a  curiously  attractive  ap- 
pearance. 


NIAGARA    CRINOIDS. 

FIG.  57 


Eucalyptocrinus  decorus. 


"Lecanocrinus  macropetalus, 


SALINA     PERIOD. 
FIG.  56. 


207 


A  Niagara  Coral  (Hall). 


SALINA     PERIOD. 

Location. — This  period  is  named  from  the  Salina 
salt  springs  near  Syracuse,  N.  Y.  The  formation  runs  in 
a  narrow  belt  parallel  with  the  Niagara  limestone,  as  far 
westward  as  Milwaukee. 

FIG.  58. 


Encrinital  Limestone,  Niagara  Period  (Hall). 

Kinds  offfoc&.—The  rocks  consist  mainly  of  shales, 
marls,  and  some  limestone.     The  saliferous  beds  are  about 


1%8  SILURIAN    AGE. 

1,000  feet  in  thickness,  showing  a  long  continuance  of  the 
peculiar  conditions  under  which  they  were  formed. 

Fossils.  —  There  are  few  organic  remains.  The  salt 
water  seems  to  have  been  unfavorable  for  the  existence 
of  animal  life. 


.—  The  Salt  Springs  of  Syracuse  have  been 
accounted  for  in  the  following  manner:  Central  New 
York  was  at  that  time  a  great  salt  lake,  shut  off  mainly 
from  the  sea.  By  continued  evaporation,  by  fresh  over- 
flows of  the  brine  from  the  ocean,  and  by  washings  of 
rains  and  streams  from  the  adjacent  land,  muddy  deposits 
were  formed,  thoroughly  impregnated  with  salt.* 


LOWER     HELDERBERG     PERIOD. 

Location. — This  period  takes  its  name  from  the 
Helderbeig  Mountains,  near  Albany,  N.  Y.  The  rocks 
gradually  disappear  in  the  western  part  of  the  State,  but 
are  conspicuous  southward  along  the  Appalachian  range, 
and  reappear  in  Maine. 

Kind  of  ffiocfc. — This  is  also  a  great  limestone 
formation,  but  differs  from  the  Trenton  and  Niagara 
groups  in  being  thickest  on  the  eastern  border.  The 
lower  beds  in  New  York  and  Virginia  are  used  for  hy- 
draulic cement,  whence  their '  name— the  "  Water-lime 
group.1' 


*  Read  Winchell's  "  Sketches  of  Creation,"  Chap.  XXVI,  on  Rock  Salt  an<3 
Gypsum. 


LOWER     HELDERBERG     PERIOD. 


129 


fossils. — The  conditions  of  life  seern  to  have  been 
eminently  favorable.  About  four  hundred  species  of  ani- 
mals have  been  discovered.  A  brachiopod  (Pentamerus 
galeatus)  is  so  common  in  some  sections  as  to  give  its 
name  to  the  rock.  A  peculiar  crustacean,  the  eurypterus 
(broad-fin),  is  allied  to  the  trilobite.  Crab-like  in  its 
organs  of  mastication,  lobster-like  in  its  prolonged  and 
segmented  body,  with  its  broad  swimming-limbs  and 


FIG.  59. 


FIG.  60. 


Pentamerus  galeatus  (Vanuxem). 


Eurypterus  remipes. 


huge  claws,  it  presents  new  and  striking 
FIG.  61.  features.  Some  species  seem  to  have 
been  six  or  eight  feet  in  length.  They 
were  the  scavengers  of  their  time,  living 
on  the  lower  forms  and  garbage  by  the 
sea-shore.  Small  cones,  called  Tentacu- 

(Hall).     ^^^  are  g 

compose  the  mass  of  the  rock. 


.—  Geography.  —  The    formation   of    lime- 
stone  during  this  period  in  eastern  New  York  and  in 


190  SILURIAN     AGE. 

the  Green  Mountain  region  shows  that  these  sections 
must  have  been  depressed,  and  the  mountains,  in  part 
at  least,  again  submerged  in  the  sea.  More  than  half  of 
New  York,  nearly  all  of  Canada  and  Wisconsin,  had  now 
become  dry  land.  A  great  bay,  however,  covered  a  large 
part  of  Michigan.  The  rivers  were  probably  small,  and 
fresh  water  lakes,  if  any  existed,  have  disappeared. 

ORISKANY     PERIOD.* 

Z<ocalion  .  —  This  formation  is  named  from  Oriskany 
Falls.  It  crops  out  at  points  in  Maine,  extends  south- 
ward along  the  Appalachian  region,  and  westward  to 
Missouri.  It  is  the  passage-rock  from  the  Silurian  to 
the  Devonian. 

l£ind  of  ffiocfc.  —  It  is  mostly  a  light,  rough  sand- 
stone, often  highly  calcareous.  Its  thickness  in  New 
York  varies  from  twenty  feet  at  the  typical  locality  to 
only  a  few  inches  toward  the  Hudson  ;  in  Pennsylvania 
it  is  200  feet  thick.  Its  color  is  white,  passing  to  a 
reddish-brown  where  iron  is  present. 


.  —  The  most  common  fossil  is  a  brachiopod 
(Fig.  62).  The  rock  is  often  made  up  of  these  character- 
istic shells  or  of  their  casts.  The  latter  are  represented 
in  Fig.  63.  It  is  a  mould  of  the  interior  of  the  shell 
formed  by  the  sand  which  filled  it,  while  the  substance 
of  the  shell  itself  has  decomposed. 


*  In  Southern  Illinois  there  is  a  formation  termed  the  Clear  Creek  limestone, 
which  seems  to  mark  a  transition  from  the  Silurian  to  the  Devonian,  since  it 
contains  \Arell-marked  fossils  of  both  ages.  It  forms  the  Mississippi  Bluffs  south 
of  Thebes. 


OR1SKANY    PERIOD. 


131 


.—  /.  This  formation  is  another  feature  of 


the  old  Appala- 
chian sea-beach. 
The  thickness  of 
the  rock,  as  it  ex- 
tends southward 
from  the  Eozoic 
area,*  indicates  a 
deepening  of  the 
water  which  cov- 
ered both  New 
York  and  New 
England,  while 
the  Green  Moun- 
tains were  a  nar- 
row island  sepa- 
rating them. 

2.     Climate. 

—  The  fossils,  con- 
stituting a  kind  of 
life  -  thermometer, 
indicate  that  the 
climate  of  the  Si- 
lurian was  uni- 
form. 


of 


'Progress 
.—  The 


FIG.  62. 


Spirifer  arenosus  (Vanuxem). 

FIG.  63. 


A  Cast  (Vanuxem). 


*  The  material  for  making  the  continent  came  always  from  the  north-east. 
For  this  reason  formations  are  generally  coarser  east,  and  finer  west.  Shales 
and  sandstones  east  often  become  limestones  west. 


1S%  S1LVR1AN    AGE. 

grand  types  of  life  remained.  Continued  changes,  how- 
ever, took  place  in  the  development  of  the  creative  idea 
by  the  disappearance*  of  old  genera  and  the  appearance 
of  new  ones.  Mollusks  continued  to  take  the  lead,  while 
the  articulates  were  as  yet  represented  only  by  the  second 
class — crustaceans.  Neither  plant  nor  animal  was  seen 
on  the  land,  and  no  fish  sported  in  the  waters. 

£.  Uniformity  of  Nature. — The  construction  of 
the  eyes  of  the  trilobite  shows  that  the  laws  of  light  were 
the  same  then  as  now.  The  animal  itself  was  very  like 
the  king-crab  of  the  Atlantic  coast.  The  orthoceratites 
were  the  progenitors  of  the  nautilus,  the  shell  being  un- 
coiled in  those  early  species.  The  sea-shore  was  clad  in 
weeds,  and  in  favorable  localities  the  waters  were  thronged 
with  inhabitants.  Species  and  genera  took  their  places 
in  the  grand  subkingdoms  of  animal  life  It  requires  no 
great  stretch  of  the  fancy  to  people  those  early  seas,  and 
imagine  the  inhabitants  busy  and  joyous  on  a  summer's 
eve  as  the  tribes  that  throng  our  existing  oceans. 

Scenic  Description. — Let  us  picture  to  ourselves 
the  scenery  of  the  Silurian  Age.  The  air,  damp  with 
fogs  and  foul  with  noxious  gases,  hangs  heavy  over  land 
and  sea.  The  sun  sheds  a  strange,  lurid  glare.  The  land, 
faintly  visible  in  the  dim  light,  presents  few  attractions. 
The  new-born  continent  is  yet  crude  and  unfinished. 
Vapor  is  rising  in  clouds  from  the  heated  surface.  With 


*  For  example,  the  chain-corals  and  graptolites  passed  away  with  the  Upper 
Silurian,  while  the  crinoids  greatly  increased.  Dana  says  that  not  one  species 
belonging  to  the  latter  part  of  the  Lower  Silurian  existed  at  the  close  of  the 
Upper  Silurian. 


SCENIC    DESCRIPTION.  133 

no  song  of  bird,  no  hum  of  insect,  no  garment  of  ver- 
dure, it  is  a  broad,  low,  barren,  rocky  desert.  Everywhere 
are  seams,  and  gnlfs,  and  ridges,  rent  and  upheaved  by 
earthquake  shocks,  and  swept  by  volcanic  floods.  The 
sea  is  the  only  centre  of  life.  The  low  rocky  beach  is 
garnished  with  innumerable  sea-weeds,  whose  long  trail- 
ing branches  rise  and  fall  with  the  tide,  while  every  wave 
strews  the  sand  with  shells  and  broken  corals,  heaped  in 
lengthened  rows  like  the  grass  from  the  mower's  scythe. 
Trilobites,  in  swarming  shoals,  scull  their  tiny  boats  in 
animated  pursuit  of  food.  Huge  orthoceratites  lie  quietly 
floating  their  many-chambered  shells  on  the  surface,  or 
speed  through  the  water  with  long  arms  spread  to  grasp 
their  prey.  The  sea-bottom  is  gay  with  the  lily-shaped 
crinoids  that,  blossoming  with  life,  foreshadow  the  flowers 
which  are  yet  to  deck  the  barren  earth.  Coral  reefs 
stretch  away  in  lines  of  beauty,  where  myriad  workers  toil 
to  build  their  fragile  many-colored  homes.  In  shallower 
places,  too,  there  is  somewhat  of  grace,  for  the  graptolites 
cover  the  muddy  bottom  with  their  quaint  mossy 
branches,  overshadowing  mollusks  that  sluggishly  luxuri- 
ate in  endless  profusion  below.  Yet  as  the  long  age  goes 
by,  continued  changes  take  place.  The  land  rises  and 
falls.  The  sea  retires,  and  anon  pours  swelling  in  again. 
The  scene  of  life  shifts  from  one  locality  to  another. 
The  great  drama  of  life  and  death  has  begun,  which  is  to 
be  played  while  the  earth  endures. 


184 


THE     DEVONIAN     AGE. 
FIG.  62. 


Fishes  of  Devonian  Sea.     i.  Coccosteus.     2.  Pterichthys.     3.  Cephalaspis.    4.  Holop- 
tychius.     5.  Osteolepis. 


DtiVO  NlA  N     A  G  E.  135 


II.    DEVONIAN    AGE. 

{4.  Catskill  Period. 
^.  Chemun£  Period. 
2.  Hamilton  Period, 
i.  Upper  Helderberg  Period. 

This  second  great  stage  in  the  progress  of  life  on  the 
earth  takes  its  name  from  the  county  of  Devon,  England, 
where  the  formation  is  very  clearly  and  extensively  de- 
veloped. It  is  often  styled  the  OLD  BED  SANDSTONE, 
from  the  prevalent  color  of  the  rock,  and  has  been  im- 
mortalized by  Hugh  Miller  under  that  name.  On  this 
continent  its  color  and  character  are  very  different, 
although  it  is  similar  in  its  dominant  fossils. 

General  Characteristics. — The  continent  is  still 
small,  low,  and  rocky.  The  Silurian  sea  is  gradually 
retiring  southward,  as  period  after  period  adds  its  belt  to 
the  growing  margin  of  the  land.  The  earth,  however,  is 
no  longer  lifeless.  Flags  and  rushes  abound  by  the 
water-courses,  while  ferns  of  rare  beauty  and  plants  very 
like  our  rushes,  nourish  in  the  marshes.  There  are  cone- 
bearing  trees,  but  no  conspicuous  flowering  tree  or  shrub 
like  the  maple  or  rose.  The  graptolites  have  become 
extinct,  while  that  curious  crustacean,  the  eurypterus, 
appears  in  profusion  in  Europe,  but  rarely  in  America. 

The  marked  feature  is  the  fishes  which  swarm  in  the 
seas.*  They  were  nearly  all  Ganoids,  i.  e.,  they  had  beau- 

*  Anderson  says  the  remains  of  these  Ganoid  fishes  are  so  ahundant  in  the 
yellow  sandstone  deposit  of  Dura  Den,  Scotland,  that  a  space  of  little  more  than 


IBS  DEVONIAN    AGE. 

tifully  enameled  scales  encasing  them  as  with  an  armor, 
and  often  a  bony  helmet  large  enough  to  cover  the  skull 
of  an  elephant,  strong  enough  to  resist  a  musket-ball,  and 
hard  enough  to  strike  fire  like  a  flint.  The  tail  was 
nearly  always  of  unequal  lobes,  instead  of  equal  lobes  or 
rounded  forms,  as  at  the  present.  Thus,  says  Agassiz, 

FIG.  64. 


i.  Heterocercal,  or  unequally  bilobate  ;   2.  Equally  bilobate ;  and,  3.  Single  and 
rounded  form  of  tail. 

the  progress  of  life  through  the  ages  has  been  marked  in 
the  tails  of  the  fishes.  Among  the  most  peculiar  of  these 
fishes  we  notice — 1.  THE  COCCOSTEUS  (berry-bone), 
which  takes  its  name  from  the  tiny  berry-like  projections 
ornamenting  its  plated  armor.  Its  teeth  are  chiseled,  as 
it  were,  out  of  the  solid  jaw,  just  as  the  teeth  of  a  saw  are 
cut  out  of  the  solid  metal.  2.  THE  PTEKICHTHYS  (wing- 
fish)  had  two  arms  or  wings,  combining  the  broad  blade 
of  a  paddle  with  the  sharp  point  of  a  spear,  which  served 
both  for  propulsion  and  for  offence.  The  head  was  cov- 
ered with  a  strong  helmet,  perforated  in  front  by  two 
circular  holes,  through  which  the  eyes  looked  out.  Its 
chest  was  protected  by  a  curiously  constructed  cuirass 
formed  of  plates,  and  the  tail  was  sheathed  in  a  flexible 

three  square  yards  yielded  above  1,000  fishes,  most  of  them  perfect  in  their  out- 
line, with  scales  and  fins  quite  entire,  and  the  forms  of  the  creatures  often  start- 
ing freely  out  of  their  hard,  stony  matrix  into  their  complete  armature  of  scale, 
fin  and  bone. 


OF    DEVONIAN    AGE.  1S7 

mail  of  bony  scales.  3.  THE  CEPHALASPIS  (buckler- 
head)  had  a  head-plate  of  a  single  bone  of  a  crescent 
shape.  4.  THE  HOLOPTYCHIUS  (all-wrinkled)  is  so  called 
from  the  curiously  wrinkled  sculpturing  that  adorned  its 
scales.  4.  THE  OSTEOLEPIS  (bony-scale)  had  bony  scales 
placed  alongside  one  another  like  the  bricks  in  a  build- 
ing, thus  affording  protection,  and  at  the  same  time 
yielding  readily  to  the  bending  of  the  body. 

In  these  fishes  there  is  a  singular  union  of  reptilian 
and  fishy  traits.  The  structure  of  their  skull  resembled 
that  in  reptiles,  while  their  air-bladders  had  a  lung-like 
character.  They  could  move  the  head  upon  the  neck 
independently  of  the  body.  Like  reptiles,  also,  their  ver- 
tebrae were  connected  by  ball-and-socket  joints  instead  of 
inverted  cones,  as  in  common  fishes. 

Comprehensive  Types. — The  Creative  purpose 
seems  at  the  beginning  to  have  been  sketched  in  broad, 
general  characters,  and  to  have  included  in  the  first  ex- 
pression of  the  plan  all  the  structural  possibilities.  This 
combination  of  higher  with  lower  features  in  the  early 
organic  forms  is  a  very  striking  peculiarity,  and  becomes 
still  more  significant  when  we  notice  that  many  of  the 
later  types  recall  the  more  ancient  ones.  The  latter  may 
be  styled  prophetic  and  the  former  retrospective  types, 
since  the  one  anticipates  the  future  and  the  other  recalls 
the  past.  The  crinoids,  with  closed  cups  in  some,  and 
open,  star-like  forms  in  others,  united  features  of  the 
present  star-fishes  and  sea-urchins,  and  by  their  stems, 
which  fastened  them  to  the  ground,  included  also  a  polyp- 
like  character.  The  armor-plated  pterichthys  propelled 
itself  with  paddle-arms,  like  the '  turtle,  instead  of  with 


188  DEVONIAN  A&E. 

the  tail,  like  other  fishes.  The  trilobites,  with  their  uni- 
form rings  and  head-shield,  partook  at  once  of  worm  and 
crustacean  types.  The  chambered  shells  of  the  ortho- 
ceratite  and  goniatite  gave  hints  of  the  ammonite  of  a 
later  age. 

The  early  fishes  prophesied  not  only  the  reptiles  which 
were  to  come,  but  also  the  birds  and  even  mammals. 
Though  the  ancient  types  have  become  obsolete,  and  have 
been  replaced  by  modern  ones,  as  Agassiz  happily  re- 
marks, a  few  old-fashioned  individuals  have  been  left 
behind  to  give,  as  it  were,  the  key  to  the  history  of  the 
race.  The  gar-pike  explains  the  ancient  Devonian  fishes ; 
the  Millepore  coral,  the  old  Silurian  corals  ;  the  nautilus, 
the  ammonite  and  orthoceratite.  The  thought  of  God 
thus  includes  all  that  have  gone  before  as  well  as  all  that 
now  exist.  The  study  of  nature  reveals  to  us  the  present 
linked  with  the  past,  which  is  not  lost  and  dead,  but  per- 
petually revivified  and  reproduced  in  the  life  of  to-day. 

UPPER    HELDERBERG  OR  CORNIFEROUS 
PERIOD. 

ZfOcalion. — The  lower  group  is  found  in  eastern 
New  York,  and  is  thickest  along  the  Appalachians ;  the 
upper  group  is  a  great  continental  limestone  like  the 
Trenton  and  the  Niagara.  At  the  west,  in  the  absence 
of  the  Oriskany,  the  Corniferous  often  lies  directly  upon 
the  Niagara  limestone,  except  where  the  Salina  rocks 
intervene. 

Kinds  of  3?oc£.—T}\is  formation  in  New  York 
comprises  two  epochs:  (1).  The  Cauda-Galli  and  Scliolm- 
rie  Grits,  which  are  named,  the  former — the  passage-rock 


HAMILTON    PERIOD.  189 

from  the  Silurian  to  the  Devonian — from  a  peculiar 
feathery  sea-weed  common  in  it,  and  the  latter  from  the 
typical  locality  in  eastern  New  York.  (2).  The  Hel- 
derberg  Limestones, — the  last  great  limestone  formation 
in  New  York — the  lower  beds  of  which  are  termed  the 
Onondaga,  and  the  upper  the  Corniferous  limestone. 

The  Helderberg  beds  lose  their  distinctive  features 
westward  and  blend  into  one  group,  which  is  called  by 
either  of  these  names.  The  Corniferous  limestone  (cornu, 
a  horn)  derives  its  appellation  from  disseminated  nodules 
of  hornstone  ("chert").  The  Onondaga  is  a  dark-gray 
rock  which  takes  an  excellent  polish.  These  limestones 
are  quarried  for  a  building-stone  at  multitudes  of  points 
throughout  western  New  York,  Ohio,  Michigan,  Indiana, 
and  Illinois. 

Fossils.  —  This  was  the  great  Paleozoic  coral  reef. 
Corals  are  found  in  every  conceivable  form — standing, 
lying  down,  broken  into  fragments,  or  preserved  as  per- 
fectly as  if  they  had  grown  but  yesterday.  They  flour- 
ished luxuriantly  and  may  have  exhibited  all  the  wealth 
of  coloring  now  manifested  in  the  tropical  seas.  They 
are  especially  abundant  at  the  Falls  of  the  Ohio,  near 
Louisville.  Some  have  a  diameter  of  five  or  six  feet. 
Crinoids  and  mollusks,  in  all  their  orders,  present  a  be- 
wildering variety  and  profusion. 

HAMILTON      PERIOD. 

ZtOcatton. — This  formation  extends  across  New 
York,  Michigan,  thence  west  of  the  Mississippi  river,  and 
southward  through  Pennsylvania,  Virginia,  and  Ten- 
nessee. 


140  DEVONIAN    AGE. 

J£inds  of  ftocfc.—  In  New  York  this  period  com- 
prises three  epochs.* 

(1).  The  Marcellus  Shale  is  a  fissile  slate,  often  nearly 
jet-black.  It  abounds  in  septaria  resembling  turtles 
(see  p.  83).  It  contains  so  much  carbonaceous  matter 
as  sometimes  to  burn  quite  freely.  This  fact  has  led 
to  much  waste  of  money  in  exploring  it  for  coal.  The 
attempts  are  always  futile,  since  the  formation  lies 
thousands  of  feet  below  the  coal  measures.  (2).  The 
Hamilton  Group  f  consists  of  a  harder  and  lighter  shaly 
sandstone,  often  calcareous.  The  layers  are  remarkable 
for  the  abundance  of  ripple-marks.  They  present  also  a 
?ery  perfect  jointed  structure,  some  fine  examples  of 
which  are  seen  on  Cayuga  Lake  (Fig.  25).  (3).  The 


*  The  Hamilton  series  in  New  York  makes  one  enormous  formation.  It  is 
nearly  destitute  of  lime,  and  thus  differs  widely  from  the  Onondaga,  Trenton, 
and  Niagara  limestones  which  overlie  it  on  the  north.  The  most  marked 
physical  features  of  this  great  extent  of  country  consist  in  its  deep  valleys  and 
long  ridgy  hills,  usually  extending  in  a  north-and-south  direction,  as  an  inspec- 
tion on  any  map  of  the  rivers  which  follow  the  valleys  will  show.  Some  of  these 
long  north-and-south  valleys,  having  been  excavated  so  deeply  below  their 
outlets  as  to  retain  the  accumulated  waters  of  the  rains  and  streams,  form  that 
remarkable  series  of  lakes  beginning  with  the  Otsego,  and  comprising  the 
Canaseraga,  Cazenovia,  Otisco,  Skaneateles,  Owasco,  Cayuga,  Seneca,  Crooked, 
•Canandaigua,  Honeoye,  Canadice,  Hemlock,  and  Conesus  lakes ;  all  so  similar  in 
their  general  form  and  direction,  and  in  the  shape  and  geological  formation  of 
their  inclosing  hills.  Over  the  whole  extent  of  these  rocks,  the  country  is  "roll- 
ing "  or  broken  into  ridges  generally  running  north  and  south,  and  rising  from 
one  to  eight  hundred  feet  above  their  main  dividing  valleys ;  and  it  is  rarely  that 
we  find  among  them  a  plain  half  a  mile  in  width,  excepting  in  a  few  of  the  "  bot- 
tom-flats "  or  alluvial  lands  along  the  larger  rivers.  (Lincklaen  in  Guide  to  N.  Y. 
State  Cabinet.) 

The  upper  part  of  Hamilton  Group  in  New  York  is  a  dark,  impure  rock,  termed 
the  Tully  limestone.  It  is  about  twenty  feet  in  thickness,  and  contains  a  few  dis- 
tinguishing fossils. 

t  The  absence  of  the  Marcellus  Group  at  the  west,  drops  the  Hamilton  directly 
upon  the  Corniferous,  forming  the  appearance  of  a  single  mass.  Thus,  four 
limestone  formations— the  Niagara,  Salina,  Corniferous,  and  Hamilton— are  there 
brought  into  juxtaposition.  Before  they  were  closely  distinguished,  the  entire 
mass  was  known  as  the  "  Cliff  limestone,"  because  they  often  formed  bold  bluffg 
along  the  river-banks. 


HAMILTON    PERIOD. 


141 


Genesee  Slate  which  overlies  the  Hamilton  beds  derives 
its  name  from  the  gorge  in  the  Genesee  river,  where  it  is 
well  developed.  It  is  a  dark  bituminous  shale,  rich  in 
oil.  Through  the  Mississippi  valley  it  is  known  as  the 
Black  Shale. 

Fossils. — The  Marcellus  Shale  contains  the  orthocer- 


atite  and  goniatite.  The 
latter  is  like  the  former, 
but  is  partly  coiled,  thus  re- 
sembling the  modern  nau- 
tilus. The  name  (gonia, 
an  angle),  refers  to  the 
sinuous  form  of  the  parti- 
tions which  separate  the 
different  chambers.  The 
Hamilton  Group,  in  its  lime- 


FIG.  65. 


Goniatite  (Vanuxem*). 

FIG.  66. 


stone  layers,  has  fine  cri- 
noids  and  corals,  but  the 
predominant  fossils  are 
brachiopods  and  conch- 
ifers,  *  —  species  which 
nourish  in  muddy  wa- 
ters. Among  the  former 


Spirifer  mucronatus  (Hall). 


*  Conchifers  (shell-bearers)  have  their  gills  in  thin  membranous  plates  on 
each  side,  as  seen  in  the  oyster,  whence  they  are  often  called  Lamellibranchs 
(Lamella,  a  plate).  A  line  let  fall  as  in  the  case  of  the  Brachiopods  (p.  118)  will 
divide  the  shell  into  two  unequal  parts. 


DEVONIAN     CORALS. 


FIG.  67. 


i.  Heliophyllum  Halli.  2.  Eridophyllum  simconensis.  3.  Favosites  goth- 
iandica.  4.  Syringopora  elegans.  5.  Aulopora  cornuta.  6.  Philipsastraea 
Verneuili.  7.  Zaphrentis  prolifera. 


CHEMUNG     PERIOD. 

are  many  beautiful  ones  belonging  to  the  family  of  spiri- 
fers.     A  peculiar  coral,  commonly  styled  the  cup  coral 
(see  1  and  7,  Fig.  67)  is  noticeable.    It  is  horn-shaped,  and 
was  occupied  by  a  single  polyp,  which,          Fig  68> 
when  alive,  with  its  tentacles  expanded, 
must  have  been  seven  or  eight  inches  in 
diameter.      Fish-bones  are  common    in 
some  localities.    A  small  trilobite  (Pha- 
cops  bufo,  lens-eyed  toad)  is  conspicuous 
because  of  the  perfect  preservation  of  its 
eye  lenses.    Terrestrial  plants  are  an  in- 
teresting feature,   since  they  now   first 
appear  in  any  abundance.  Phacops  bufo  (ffaU). 


CHEMUNG     PERIOD. 

JjOCCtHon. — The  Chemung  formation  is  found  in  New 
York,  and  attains  a  great  thickness  in  Pennsylvania. 

ICinds  of  ffiocfc. — This  period  contains  in  New 
York  two  epochs.  (1).  The  Portage  Group  receives 
its  name  from  the  celebrated  falls  in  the  Genesee  River. 
It  consists  of  shales  and  sandstones,  which  are  nearly 
1000  feet  thick  at  that  locality.  (2).  The  Chemung 
Grovp,  named  from  the  Narrows  in  the  Chemung  * 
River,  is  composed  of  coarse  shales  and  shaly  sandstones 
of  an  olive  or  a  greenish  color.  All  the  rocks  abound  in 
ripple-marks,  mud-cracks,  and  other  proofs  of  broad,  low 
flats,  swept  by  a  muddy  sea.f 


*  The  name  Chemung — meaning  big  horn — was  given  to  it  by  the  Indians  be- 
cause of  a  mammoth  tusk  which  they  found  in  the  bed  of  the  river. 

t  Hall  well  remarks,  here  quiet  was  required  for  the  growth  of  the  abundant 
forms  of  Brachiopods  and  Lamellihranchs. 


144  DEVONIAN    AGE. 

Fossils. — The  Portage  contains  few  fossils.  The 
Chemung,  however,  abounds  in  organic  remains.  Large 
slabs  are  completely  covered  with  impressions  of  shells. 
Brachiopods  and  conchifers  are  plentiful,  and  occasionally 
a  trilobite  or  an  orthoceratite  is  met.  A  prominent 
brachiopod  is  the  broad-winged  spirifer,  which  is  com- 
monly known  as  a  "petrified  butterfly."  It  resembles  the 
one  shown  in  Fig.  66.  Beautiful  fern  impressions  are 
also  presented — a  prophecy  of  the  abundant  vegetation  of 
the  Carboniferous  Age. 

CATSKILL     PERIOD. 

ZfOCation. — This  formation  constitutes  the  upper 
range  of  the  mountains  after  which  it  is  named.  It  is 
there  perhaps  2500  feet  thick,  while  south,  along  the 
Appalachians,  it  is  more  than  twice  that  thickness. 

l£inds  of  *Kocfc. — The  beds  consist  of  shales  and 
sandstones,  of  a  greenish  or  a  reddish  color,  and  often- 
times gritty  character.  The  harder  strata  of  the  sand- 
rock  sometimes  weather  in  a  peculiar  way,  dividing  into 
thin  layers  resembling  a  pile  of  boards. 

FIG.  680. 


Modiola  Angusta  (Vanuxem). 


CATSKILL     PERIOD. 


Fossils.  —  There  are  few  organic  remains.  Tiny 
seams  of  coal,  as  in  the  Chemung  rocks,  indicate  the  pres- 
ence of  plants,  while  bones  and  scales  of  fish,  often  white 
or  blue,  are  conspicuous  on  the  red-shale. 


*  —  Geography.  —  New  York  and  Wisconsin 
were  nearly  finished.  Interior  Michigan  was  yet  an  inland 
sea,  while  the  ocean  washed  in  unrestrained  freedom  the 
vast  area  of  the  Mississippi  valley.  The  Hudson  and 
Connecticut  Elvers  were  perhaps  formed,  and  the  St. 
Lawrence  emptied  into  the  sea  near  Montreal. 

Scenic  Description.  —Let  us  try  to  picture  to 
ourselves  a  scene  in  the  Devonian  landscape.  The  air 
is  yet  heavy  with  mist,  and  we  strain  our  eyes  to  catch 
a  view  of  the  land,  like  a  voyager  before  whom,  amid 
the  fogs  and  dews  of  early  twilight,  looms  an  unknown 
shore.  Gleams  of  light  here  and  there  reveal  to  us  hill- 
sides green  with  forests  of  lofty  ferns  and  club  mosses 
of  gigantic  size.  Insects,  the  only  winged  animals 
yet  created,  flit  in  and  out,  enlivening  the  solitude  with 
their  ceaseless  hum.  The  rivers,  fringed  with  tall,  slender 
rushes  and  reeds,  look  almost  familiar  ;  but  no  grass  car- 
pets the  meadows,  no  moss  clings  to  the  rocks,  no  flowers 
deck  the  landscape. 

The  sea-shore,  however,  is  stirring  with  life.  Eurypteri 
crawl  over  the  slimy  bottom,  and,  thrusting  out  their  long 
muscular  arms,  draw  into  their  voracious  maws  sea-weeds, 
fish,  and  other  organic  remains  thrown  up  by  the  tide. 
Innumerable  fish,  the  armor-clad  pirates  of  the  Devonian 
seas,  impregnable  against  attack,  dart  through  the  water 
in  eager  pursuit  of  their  prey,  which  they  crush  between 


IJfi  DEVONIAN     AGE 

their  poniard-like  teeth.  In  the  deeper  waters  the  coral 
tribes  are  busily  at  work,  clearing  the  water  and  building 
up  the  continent,  while  on  the  shallow,  muddy  bottoms, 
shell-fish  congregate  in  myriads,  furnishing  food  for  the 
rapacious  monsters  of  the  deep. 

Nowhere  in  the  rocky  book  of  Nature  do  we  read  a 
page  of  quiet,  free  from  pain  or  death.  From  the  begin- 
ning the  flesh-eater  preyed  on  the  plant-eater,  and,  as  now, 
the  weak  succumbed  to  the  strong.  The  struggle  for  ex- 
istence began  with  its  gift,  and  the  reign  of  death  was  in- 
augurated by  the  enjoyment  of  life.  Thus  only  can 
Nature  preserve  the  equipoise  between  growth  and  decay, 
between  the  means  of  subsistence  and  the  development  of 
life. 

FIG.  69. 


Orthis  hipparionyx. 


DEVONIAN    FOSSILS. 
FIG.  690. 


i.  Dalmanites  selenurus  (Halt).  2.  Cyrtoceras  undulatum. 
undulata  (Hall).  4.  Orthis  lenticularis.  5.  Atrypa  reticularis. 
Ichthyodolerite  (a  defensive  fin-bone). 


3.  Strophomem 
6.  Section  of  an 


DEVONIAN    FOSSlLa 
FIG. 


i   Cyrtoceras.    Back  view,  showing  the 
undulating  septae. 


».  Ichthyodolerite  (fin-bone)  of  Ooon 
daga  Limestone  (Hall). 


CARBONIFEROUS    AGE. 


149 


III.     CARBONIFEROUS    AGE. 

(3.  Permian  Period. 
CARBONIFEROUS  AGE.  •}  2.  Carboniferous  Period. 

(  i.  Sub-carboniferous  Period. 

This  age  is  so  named  from   the  abundance  of   coal 
formed  in  its  time. 


FIG.  6qc. 


A  Carboniferous  Fern  (Sphenopteris  Egyptiaca). 


General    Characteristics -.—At  the  beginning  of 
the  age  the  growing  continent  had  increased  by  the  sue- 


150  CARBONIFEROUS    AGE. 

cessive  additions  of  the  Silurian  and  Devonian  Ages,  so 
that  the  shore-line  of  the  Atlantic  extended  through 
southern  New  York,  thence  west  through  the  southern 
part  of  Ohio,  across  the  future  Mississippi  valley.  The 
Gulf  of  Mexico  reached  north  to  central  Iowa.  Lake 
Superior  was  the  only  one  of  the  great  lakes  in  existence. 
The  pressure  of  the  waters  in  the  Atlantic  and  Pacific 
oceans  gradually  deepened  their  beds  and  produced  a 
corresponding  uplift  of  the  future  continent,  so  that  after 
a  time  the  water  drained  off  the  site  of  the  present 
southern  and  the  middle  States  south  of  the  coast  line 
against  which  the  warm  water  of  the  Gulf  had  beaten  so 
long.  The  low  muddy  tracts,  the  former  sea-bottom, 
became  a  wide  extended  marsh,  warmed  to  a  tropical 
temperature  by  the  internal  heat.  The  atmosphere, 
dense  with  moisture,  and  containing,  in  the  form  of 
carbonic  acid,  all  the  carbon  now  locked  up  in  the  coal- 
beds,*  was  rich  in  vegetable  food.  These  favorable  con- 
ditions rendered  the  earth  a  very  green-house,  fit  to  teem 
with  luxuriant  vegetation.  This  same  acid,  however, 
would  have  been  fatal  to  air-breathing  animals.  Hence 
before  they  could  be  introduced,  the  atmosphere  must  be 
prepared  for  their  use.  Here  came  a  pause,  as  it  were,  in 
the  progress  of  the  animal  life  of  the  world.  The  plant 
must  purify  the  air  for  the  animal.  The  All-creative 
Hand,  suiting  the  means  to  the  end,  at  once  covered  the 
land  with  a  new  and  teeming  flora.  Forests  of  strange 
form  and  prodigious  size  sprang  up  as  if  by  magic  to 
meet  this  new  demand  of  Nature.  No  change  of  climate 


*  The  atmosphere  now  contains  1  part  in  2,500  of  carbonic  acid.    According 
to  M.  Brongniart,  it  had  from  7  to  8  parts  in  100  in  the  Carboniferous  Era. 


CARBONIFEROUS    AGE.  151 

varied  the  productions  of  the  ground,  but  everywhere 
flourished  the  same  tropical  growth.  The  crust  of  the 
earth  was  unsteady,  and  frequent  elevations  and  depres- 
sions alternated.  At  one  time  it  was  lifted  up  to  be 
covered  with  vegetation,  and  at  another  sunk  with  the 
ruins  of  the  forests  below  the  incoming  ocean  to  receive 
a  deposit  of  sedimentary  rocks.  The  theater  of  these  re- 
peated changes  was  the  whole  of  the  present  coal  area, 
and  much  besides  from  which  the  coal  has  been  swept 
by  subsequent  denudation.  During  a  season  of  verdure  a 
vast  amount  of  vegetable  debris,  such  as  leaves,  limbs, 
fallen  trunks,  etc.,  accumulated,  only  to  be  overwhelmed 
by  the  flood  of  sand,  pebbles  and  mud  washed  in  by  the 
rushing  waters.  The  peat-deposit  gradually  changed  to 
coal,  and  the  sediment  hardened  to  shales,  sandstone,  or 
clay.  Sometimes  the  water  became  deep  and  clear 
enough  for  corals  or  mollusks  to  exist,  and  Nature,  suit- 
ing the  life  to  the  new  condition,  populated  the  shallow 
sea  with  swarming  millions,  and  there  a  limestone  was 
interpolated. 

Perhaps  a  hundred  times  in  the  course  of  the  age  this 
process  was  repeated,  and  as  many  alternate  layers 
chronicled  the  changes  in  regular  succession.  In  a  Nova 
Scotia  coal-bed  Lyell  found  in  a  portion  1,400  feet  thick 
no  less  than  sixty-eight  levels,  showing  as  many  different 
old  soils  of  forests,  one  above  the  other,  where  the  trunks 
of  trees  were  still  furnished  with  roots. 

These  characteristics  culminated  in  the  Carboniferous 
Period  of  the  age,  being  preceded  by  the  Sub-carbonifer- 
ous and  followed  by  the  Permian,  in  both  of  which  the 
land  of  these  formations  was  submerged  by  the  sea,  re- 
ceiving mainly  rock  deposits. 


CARBONIFEROUS    AGE. 


SUB-CARBONIFEROUS     PERIOD. 

ZtOcation.  —  This  formation  is  so  named  because  it  is 
the  base  of  the  great  carboniferous  system  of  the  con- 
tinent. It  is  found  in  the  Appalachian  region,  and  west- 
ward through  Iowa,  Illinois,  and  Mississippi. 

J£inds  of  ffiocfc  .  —  In  the  Appalachians  it  is  a  vast 
deposit  of  sandstone  and  shale  often  several  thousand  feet 
thick.  At  the  West*  it  is  a  compact  yellowish  or  grayish 
limestone,  of  great  thickness  and  wide  extent.  Thin 
seams  of  coal  sometimes  occur,  and  these  beds  are  known 
as  the  False  Coal  Measures. 


.  —  The  limestone  abounds  in  crinoids.  No- 
where else  are  these  stone-lilies  —  the  blossoms  of  the  Sub- 
carboniferous  sea  —  found  in  such  profusion  and  beauty. 
There  are  also  many  brachiopods  and  fish  remains.  In 


*  The  following  are  the  subdivisions  in  Illinois  as  given  by  Worthen  : 

1.  The  Chester  Group,  500  to  800  feet  thick. 

2.  The  St.  Louis  Group,  50  to  200  feet  thick,  which  is  cavernous.    There   are 
many  sink-holes  in  it  near  St.  Louis  showing  the  mouths  of  these  caves. 

3.  The  Keokuk  Group,  100  to  150  feet  thick.    This  contains  numerous  geodes, 
varying  from  \  inch  to  two  feet  in  diameter,  lined  with  beautiful  crystals  of 
quartz,  calcite,  etc. 

4.  The  Burlington  Limestone,  25  to  200  feet  thick,  which  is  almost  a  mass  of 
crinoids.    Over  300  species  of  these  "  Lily  stars  "  have  been  discovered  and  new 
ones  are  constantly  being  brought  to  light. 

5.  The  Kinderhook  Group,  100  to  150  feet  thick. 

The  Marshall  Group,  so  named  from  Marshall,  Michigan,  is  doubtless,  in  part 
at  least,  of  this  period.  It  is  worked  at  Cleveland  and  Waverly,  Ohio,  furnishes 
the  grindstones  of  Berea  and  Huron,  and  underlies  the  limestone  bluff  at  Bur- 
lington, Iowa.  This  is  overlaid  in  Michigan  by  the  Michigan  Salt  Group,  which 
underlies,  like  a  great  dish,  the  whole  peninsula.  In  the  Saginaw  Valley,  deep 
wells  were  sunk  for  salt  under  the  direction  of  Alexander  Winchell,  then  State 
Geologist,  and  the  result  amply  vindicated  the  correctness  of  what  was  to  him  at 
the  time  a  mere  scientific  deduction.  The  Mountain  Limestone,  so  well  exposed 
at  Grand  Kapids,  is  the  highest  group  in  the  Sub-carboniferous. 


CARBONIFEROUS     PERIOD.  15S 

England  this  rock  is  termed  the  Mountain  Limestone. 
When  the  stone  is  worn  away  by  the  elements,  the  round, 
hard  joints  of  the  crinoids  are  found  lying  loose  in  the 
soil,  and  are  gathered  and  strung  as  beads  by  the  children.* 


.  —  /.  Caves.  —  Several  celebrated  caves  are 
in  this  rock;  for  example,  the  Mammoth  Cave,  the 
"Wyandotte  Cave,  etc.  In  many  places  in  Indiana  and 
Kentucky,  "sink-holes"  are  abundant,  sometimes  so 
numerous  as  to  interfere  with  plowing.  These  are  open- 
ings in  the  earth  where  the  soil  has  been  washed  down 
probably  into  subterranean  caves  never  yet  seen  by  man 
The  Mammoth  Cave  is  the  largest  in  the  world.  It  has 
been  explored  to  a  distance  of  over  thirty  miles.  Views 
of  the  grandest  description  are  here  presented.  Royal 
thrones,  sparry  grottoes,  diamond  arches,  flowers  of  every 
zone  sparkling  with  crystalline  beauty,  here  and  there 
reflect  the  light  of  the  traveler's  torch.  Halls  deco- 
rated with  fantastic  pillars,  and  marble  statues  draped 
with  crystal  mantles,  charm  with  their  magical  splendor. 
At  one  point  the  River  Styx  rolls  its  sad  waters  beneath 


*  Thus  Sir  Walter  Scott,  in  allusion  to  the  popular  fable  concerning  this  for. 
siation,  eays : 

"  But  fain  St.  Hilda's  nuns  would  learn 
If  on  a  rock  by  Lindisferne 
St.  Cuthbert  sits,  and  toils  to  frame 
The  sea-born  beads  that  bear  his  name : 
Such  tales  had  Whitby's  fishers  told, 
And  said  they  might  his  shape  behold, 

And  hear  his  anvil  sound, — 
A  deadened  clang,  a  huge,  dim  form, 
Seen  but  and  heard  when  gathering  storm 

And  night  were  closing  round." 

Hugh  Miller  humorously  remarks  that  if  St.  Cuthbert  made  all  these  beads,  he 
must  have  been  the  busiest  saint  in  the  calendar. 


154  CARBONIFEROUS  AG£. 

dark  vaults,  the  windings  of  which  are  indented  by  a 
thousand  rocks.  In  its  dismal  depths  gropes  a  kind  of 
fish— the  Cyprinodon — which  is  blind,  as  it  should  be, 
since  of  what  service  are  eyes  where  absolute  darkness 
reigns  ? 

2.  ^Reptiles.—  In  Sub-carboniferous  rocks  at  Potts- 
ville,  Pa.,  the  footprints  of  a  reptile,  having  a  stride  of 
thirteen  inches,  have  been  found.  Later  in  the  age,  there 
appear  many  advance  scouts,  as  it  were,  of  the  reptilian 
hosts  of  the  succeeding  age. 


CARBONIFEROUS     PERIOD. 


.  —  The  great  coal-beds  of  the  country  lie  in 
six  detached  areas  as  seen  in  the  Frontispiece.  They  are 
styled  respectively  the  Ehode  Island,  Appalachian,  Michi- 
gan, Illinois,  Missouri,  and  Texas  coal-fields.  The  Rhode 
Island  is  the  smallest,  and  comprises  an  area  of  only 
1,000  square  miles;  the  Missouri  is  the  largest,  and  covers 
100,000  square  miles.—  (Foster.) 

ICinds  of  ftocfc.  —  The  Carboniferous  Period  was 
inaugurated  by  the  formation  of  a  conglomerate  sand- 
stone, the  Millstone  Grit.*  During  this  era  the  Devonian 
fishes  and  ferns  were  buried  beneath  vast  deposits  of  sand 
and  gravel.  Times  of  semi-emergence  intervened,  when? 


*  The  ledges  of  this  conglomerate  often  separated  into  huge  blocks.  Where  a 
portion  has  been  swept  away  during  subsequent  geologic  changes,  the  remains 
present  a  striking  resemblance  to  the  streets  and  blocks  of  a  ruined  city.  Sev- 
eral of  these  so-called  "  Rock  cities"  are  situated  in  southwestern  New  York. 


THE     CARBONIFEROUS     PERIOD.          155 

for  a  brief  interval,  the  land  was  partially  clothed  with 
vegetation.  The  coal-measures  proper  present  stratified 
rocks  of  every  kind  — sandstone,  shales,  limestone,  etc. 
They  can  be  distinguished  from  Silurian  or  Devonian 
strata  only  by  the  fossils.  There  is  generally  about  one 
foot  of  coal  to  fifty  feet  of  rock.  The  thickness  of  the 
coal-bed  is  at  some  places  only  that  of  paper,  and  at 
others  from  thirty  to  forty  feet.  The  "  mammoth  vein  " 
exposed  to  view  at  Wilkesbarre,  and  worked  at  Carbon- 
dale,  Mauch  Chunk,  Shamokin,  etc.,  is  29J  feet  thick.* 
The  Pittsburg  seam  is  8  feet  thick,  and  may  be  traced  for 
a  long  distance  as  a  conspicuous  black  band  along  the 
high  banks  of  the  Monongahela.  The  miners  estimate 
that  a  coal-bed  gives  1,000,000  tons  to  the  square  mile 
for  every  foot  of  thickness.  Iron  ore  is  also  abundant. 
Iron  pyrites  (Iron  disulphide)  is  distributed  either  in 
nodules,  often  of  many  pounds  weight,  or  in  thin  seams, 
so  as  greatly  to  injure  the  coal.  The  best  quality  of  coal 
contains  a  trace  of  this  impurity,  which  gives  the  disagree- 
able odor  of  coal-gas. 

Fossils. — I.  PLANTS  are  the  characteristic  fossils  of 
this  period.   Everywhere  the  shales  bear  impress  of  the  deli- 


*  "  The  amount  of  vegetable  matter  in  a  single  coal-seam  six  inches  thick  is 
greater  than  the  most  luxuriant  vegetation  of  the  present  day  would  furnish  in 
1,200  years.  Boussingault  calculates  that  luxuriant  vegetation  at  the  present 
day  takes  from  the  atmosphere  about  half  a  ton  of  carbon  per  acre  annually,  or 
fifty  tons  per  acre  in  a  century.  Fifty  tons  of  stone-coal,  spread  evenly  over  an 
acre  of  surface,  would  make  a  layer  of  less  than  one-third  of  an  inch.  But  sup- 
pose it  to  be  half  an  inch,  then  the  time  required  for  the  accumulation  of  a  seam 
of  coal  three  feet  thick— the  thinnest  which  can  be  worked  to  advantage— would 
be  7,200  years.  If  the  aggregate  thickness  of  all  the  seams  of  coal  in  any  basin 
amounts  to  sixty  feet,  the  time  required  for  its  accumulation  would  be  144,000 
years.  In  the  coal  measures  of  Nova  Scotia  are  seventy-six  seams  of  coal,  of 
which  one  is  twenty-two  feet  thick,  and  another  thirty-seven," — Winches  Geo- 
logical 


156  THE     CARBONIFEROUS     AGE. 

cate  tracery  of  ferns,  leaves,  stems,  depicted  with  the 
sharpest  outlines.*  Trunks  of  trees,  erect  or  prostrate, 
appear  with  their  roots  yet  imbedded  in  the  layer  of  clay, 
the  very  soil  in  which  they  grew,  underneath  the  coal. 
These  fossils  reveal  to  us  most  perfectly  the  vegetation  of 
the  Period.  It  is  the  fulfillment  of  that  which  scantily 
appeared  in  the  Devonian  Age.  It  was  almost  entirely  a 
flowerless  growth.  The  leading  forms  were  tree-ferns, 
rushes,  and  club-mosses,  which  grew  to  a  size  unknown 
in  our  climate.  If  we  should  collect  the  cryptogams 
(flowerless  plants)  of  North  America  to  form  a  forest, 
it  would  hardly  overtop  a  man's  head,  and  the  ferns 
would  have  an  undergrowth  of  toad-stools,  mosses,  and 
lichens  (Dana). 

1.  The  Ferns. — Ferns  which  to-day  creep  at  our  feet, 
then  towered  into  stately  trees,  with  trunks  a  foot  and  a 
half  in  diameter.     They  are  abundant  fossils,  and  doubt- 
less contributed  most  to  the  formation  of  coal. 

2.  The  Calamites  were  jointed,  rush-like  plants.    Un- 
like the  "  horse-tail "  or  "  scouring  rushes "  of  the  pres- 
ent, which  are  rarely  two  feet  long,  their  Carboniferous 
prototypes  shot   up   like   a   gigantic   asparagus,   with   a 
woody  fiber,  to  a  height  of  a  score  or  more  of  feet.     The 
impressions  of  their  huge  prostrate  stems  are  frequent. 

*  "  The  most  elaborate  imitations  of  living  foliage  upon  the  painted  ceilings 
of  Italian  palaces,  hear  no  comparison  with  the  beauteous  profusion  with  which 
the  galleries  of  these  instructive  coal  mines  are  overhung.  The  roof  is  covered 
as  with  a  canopy  of  gorgeous  tapestry,  enriched  with  festoons  of  most  graceful 
foliage,  flung  in  wild  irregular  profusion  over  every  portion  of  its  surface.  The 
effect  is  heightened  by  the  contrast  of  the  coal-black  color  of  these  vegetables 
with  the  light  ground-work  of  the  rock  to  which  they  are  attached.  The  spec^ 
tator  feels  himself  transported,  as  if  by  enchantment,  into  the  forests  of  another 
world ;  he  beholds  trees  of  forms  and  characters  now  unknown  upon  the  sur- 
face of  the  earth,  presented  to  his  senses  almost  in  the  beauty  and  vigor  of  their 
primeval  life."— Dr. 


THE     CARBONIFEROUS     PERIOD.  157 

3.  Tfie   Sigillaria    (seal  -  marked)    is    curiously   orna- 
mented with  vertical  ribs,  along  each  of  which  is  a  row 
of  seal-like  impressions.     These  are  the  scars  left  where 
the  leaves  fell  off.     They  wind  in  a  spiral  around  the 
trunk.     The  roots  (stigmarice)  are  also  dotted  with  scars. 
They  are  generally  found  separate,   though   sometimes 
combined   with   the  parent  tree.     The   sigillarian   tree- 
trunks  frequently  occur  standing  in  coal   mines.      The 
miners  sometimes  cut  them  off  below,  when  their  taper- 
ing form  permits  the  whole  mass  to  descend  upon  the 
workmen  beneath.    These  "  coal-pipes,"  as  they  are  styled, 
are  therefore  much  dreaded. 

4.  The   Lepidodendra   (scaly-stems) — the   club -mosses 
of  that  time — were  lofty  trees,  sixty  feet  high,  with  pitted 
trunks  and  branches.     The  scars  are  arranged  diagonally 
or  in  a  quincunx  order. 

5.  Conifer sy  or  cone-bearing  trees,  were  not  infrequent, 
with  their  boughs  laden  with  fruit.     Such  was  the  vege- 
tation which   flourished   in  the  Carboniferous  Age,  and 
which  we  now  use  to  warm  and  light  our  houses  and  to 
drive  our  engines. 

II.  ANIMALS. — In  a  coal  mine  near  the  Bay  of  Fundy, 
in  the  stumps  of  two  sigillariae,  there  have  been  found  the 
remains  of  several  small  reptiles  bearing  frog-like  and 
lizard -like  forms,  a  centipede,  and  the  shells  of  a  lancl 
snail.  These  little  creatures  had  probably  crept  into  the 
hollow  trees  for  shelter,  and  were  overtaken  by  the  con- 
vulsions which  overwhelmed  them.  Several  true  reptiles 
have  since  been  identified.  Traces  of  the  spider,  cock- 
roach, scorpion,  and  May-fly  with  gauze  wings  7  inches 
broad,  have  also  been  discovered.  Remains  of  fishes, 


CARBONIFEROUS  FOSSILS. 


j.  Calamites  cistii. 

3.  Asterophyllites  equisetifornus. 

5.  Sigillaria  attenuata. 

7.  Pentremites 


2.  Archimedes   Worthenn. 

4.  Actinocrinus  Chrystii. 

6.   Pentremites    godoni. 

formis.  8.  Pentremites    Koninckana. 

6,  7  and  8  are  varieties  of  Crinoids.) 


THE     CARBONIFEROUS     PERIOD.          161 

brachiopods,   crinoids    and  corals  are    abundant.      (See 
Fig.  70.) 

Scenic  Description.— In  Fig.  71  is  an  at- 
tempt to  reproduce  the  characteristic  features  of  a  car- 
boniferous landscape.  On  the  right  are  two  naked  trunks 
of  a  lepidodendron  and  sigillaria  (whose  foliage  is  entirely 
unknown);  between  them  is  a  tall  tree-fern  with  its  um- 
brella-like top.  At  the  foot  of  these  great  trees  are 
smaller  ferns,  and,  in  front,  a  stigmaria,  whose  curiously 
dotted  and  branching  roots  reach  out  into  the  water.  On 
the  extreme  left  is  an  asterophyllite,  like  the  calamite, 
with  its  gigantic  bamboo-like  trunk.  Next  is  a  conifer, 
with  a  few  pine-like  branches.  In  front  is  a  sigillaria, 
and  at  its  foot,  prostrate,  a  sigillaria  and  a  lepidoden- 
dron mingled  with  ferns  and  vegetable  debris.  In  the 
centre  is  a  clump  of  smaller  lepidodendra.  The  back- 
ground is  filled  with  tall  calamites.  In  the  foreground 
are  the  asparagus-like  buds  of  young  calamites  just  rising 
out  of  the  water.  At  the  right  several  tiny  stems  of 
asterophyllites  show  their  pretty,  finely-cut  branches.  In 
the  water  float  two  fishes,  and  the  archegosaurus  shows 
its  long-pointed  head. 

What  a  strange  scene  is  presented  as  we  stem  the 
muddy  current  of  the  sluggish  rivers,  or  thread  the 
mazes  of  those  tropical  jungles.  It  is  as  if  the  plants 
of  a  wet  meadow  had  shot  up  into  forest  trees.  The 
trunks,  not  gnarled  and  rough  as  in  modern  times, 
spring  up  like  the  sculptured  shafts  of  a  medieval  temple, 
graceful  in  proportion  and  rich  in  ornament.  Each  col- 
umn is  embossed  with  its  varied  fluting  spirals  and  ovals 
of  curiously  intricate  patterns.  The  tall  ferns  at  every 


162  THE      CARBONIFEROUS     AGE. 

breath  of  wind  wave  their  feathery  crowns  like  beautiful 
plumes.  The  scent  of  the  morning  air  is  hoi  and  damp 
as  that  of  a  greenhouse.  The  sky,  ever  somber  and 
veiled,  shuts  down  heavy  with  oppressive  clouds.  A  wan 
and  dubious  light  scarcely  makes  visible  the  tangled 
stems  of  lepidodendra  and  sigillarise,  and  sheds  a  vague 
and  shadowy  hue  of  horror  over  the  scene.  The  flowers, 
few  and  inconspicuous,  fail  to  enliven  the  somber  tints 
with  a  gayer  color.  No  bird  fills  the  air  with  music. 
The  shrill  notes  of  insects  and  the  croaking  of  amphi- 
bians alone  wake  the  echoes  of  this  dismal  forest. 


THE    PERMIAN     PERIOD. 


.  —  This  formation  is  named  from  the  an- 
cient kingdom  of  Permia,  in  Russia,  where  it  was  first 
recognized.  It  is  wanting  in  the  older  States,  but  is 
well  developed  in  Kansas,  and  has  been  recognized  in 
Nebraska  and  Texas. 

Kinds  of  jRocfc.  —  Limestones  predominate,  though 
sandstone,  shales,  etc.,  are  found.  At  Manhattan,  Kan., 
a  limestone  is  quarried  from  this  series  for  architectural 
purposes,  which  is  so  soft  that  it  may  be  sawed  with  a 
hand-saw  and  planed  with  a  jack-plane,  and  yet  is  very 
durable.  It  is  the  cheapest  material  of  which  the  pioneer 
can  construct  his  house  —  cheaper  even  than  it  would  be 
to  resort  to  the  forest,  if  such  existed,  for  logs  (Foster). 
Hay  den  notices  the  occurrence  of  a  similar  limestone, 
and  belonging  to  the  same  age,  in  Nebraska.  The  best 
building  material  in  England  is  the  Permian  lime- 


TBE    PERMIAN    PERIOD.  163 

stone  of  which  the  new  houses  of  Parliament  are  con- 
structed. 

Fossils.  —  The  Permian  system  is  more  a  new  rock- 
formation  than  a  new  life-period.  Many  of  its  forms  are 
identical  with  those  of  the  Carboniferous  Period.  The 
air  has  been  cleared  by  the  action  of  the  abundant  vege- 
tation, and  the  empire  of  animal  life  trembles  between 
the  fishes  and  reptiles.  The  former  are  decreasing,  while 
the  latter  are  increasing  in  size  and  number.  Crocodilian 
reptiles,  their  teeth  set  in  sockets,  mark  the  transitions  of 
the  time.  The  coal  flora  has  not  entirely  died,  though 
the  coal-making  epoch  is  passed;  the  low  swampy  lands 
seem  to  have  been  raised  so  as  to  be  unfavorable  to  its 
growth,  and  no  new  vegetation  fills  the  place.  It  is  near- 
ing  the  close  of  the  great  Paleozoic  Time.  Older  forms 
are  dying,  and  the  Creator  develops  no  fresh  world- 
thoughts  to  mark  the  dawn  of  a  new  era.  The  coal  is 
stored  in  the  earth,  and  the  continent  now  moves  forward 
in  its  preparation  for  the  advent  of  man,  for  whom  it  has 
been  so  wonderfully  contrived. 


.—  /.    AppalacJrian  3tevo2ulio?i  .  —  The 

close  of  the  Paleozoic  Age  was  marked  by  a  grand  up- 
heaval. Few  if  any  animals  or  plants  survived  the  catas- 
trophe.* The  contraction  of  the  earth's  crust  caused  by 
its  gradually  cooling  or,  as  some  geologists  think,  the 


*  It  should  be  noticed  that  a  very  large  school  of  geologists  hold  that  Nature 
moves  always  by  imperceptible  stages  and  not  by  sudden  bounds  ;  that  hence 
such  phrases  as  "general  extinctions  "  and  such  words  as  "catastrophe"  and 
"  convulsions  "  are  rarely,  if  ever,  true  to  fact ;  and  that  the  Appalachian  Revolu- 
tion itself  was  accomplished  not  by  a  violent  disruption,  but  by  a  slow  move- 
ment of  perhaps  only  a  few  feet  or  yards  in  a  century.  In  a  sentence  there  may 
be  condensed  the  work  of  an  age. 


164  CARBONIFEROUS    AGE. 

tremendous  pressure  of  the  two  oceans,  had  kept  the 
newly-formed  continent  continually  vibrating  to  and  fro; 
but  at  last  the  tension  was  too  great,  and  the  crust  was 
gradually  but  irresistibly  upheaved  in  gigantic  folds 
thousands  of  feet  high,  extending  from  Vermont  to  Ala- 
bama. The  Appalachians,*  being  nearest  the  Atlantic 
force,  were  thrown  up  far  higher  than  they  are  at  present, 
often  toppling  over  from  their  dizzy  heights,  while  more 
gentle  elevations  were  made  toward  the  central  portion  of 
the  continent.  Since  then  many  of  these  folds  have  been 
denuded.f 

Mesomorphic  Action.—  During  this  fearful  and 
probably  long-continued  earth-storm  the  horizontal  coal- 
beds  were  not  only  folded  and  dislocated,  but  also  lifted 
above  their  former  level.  An  evolution  of  the  internal  heat 
with,  perhaps,  also  the  heat  produced  by  the  motion  of  the 
rocks,  metamorphosed  the  bituminous  coal  into  anthracite. 
This  effect,  like  that  seen  in  the  rock  strata,  was  most 

*  According  to  Dana,  the  material  of  the  Appalachian  Mountains  was  depos- 
ited gradually,  through  the  preceding  ages,  in  a  trough  caused  by  the  slow  set- 
tling of  the  earth  in  that  region  until  it  had  reached  a  depth  of  40,000  feet.  During 
the  Appalachian  Revolution  the  crust,  weakened  by  the  melting  off  below,  col- 
lapsed, and  the  deposits  of  the  trough  were  forced  together,  folded,  and  meta- 
morphosed as  above  described.  Hunt  holds  that  in  general  the  folding  and  ele- 
vation of  strata  are  merely  incidental  and  not  necessary  to  the  formation  of 
mountains.  The  sculpturing  agents  (see  p.  87),  which  have  carved  out  the  earth's 
present  features,  have  left  the  hills  while  digging  out  the  rest  of  the  land.  The 
mountains,  in  such  cases,  are  the  remains  of  great  table-lands,  which  have  been 
swept  away  in  subsequent  geologic  changes. 

t  A  striking  illustration,  occurring  near  Chambersburg,  Pa.,  has  already  been 
alluded  to  on  p.  82.  At  that  point,  along  a  fracture  of  twenty  miles  in  extent, 
rocks  of  the  Upper  Silurian  lie  opposite  those  of  the  Lower.  A  man  can  stand 
astride  the  crevice  with  one  foot  on  Trenton  limestone  and  the  other  on 
Hamilton  slates,  and,  in  addition,  put  his  hand  on  some  great  fragments  of  Oneida 
conglomerate,  caught  as  they  were  falling  down  the  chasm,  and  held  in  its  earth- 
quake jaws.  All  the  strata  between  these  two  extremes,  at  the  time  of  the  Ap- 
palachian Revolution,  must  have  formed  an  immense  wall  20,000  feet  high  and 
twenty  miles  in  length. 


THE    PERMIAN    PERIOD.  165 

felt  near  the  Atlantic  coast;  hence  we  find  anthracite 
coal  in  the  Appalachian  Mountains,  next  semi-bitumin- 
ous, and  in  the  western  area  bituminous  coal  alone.  The 
same  metamorphic  force,  where  greatest,  as  in  the  eastern 
States,  produced  granite,  gneiss,  and  other  crystalline  rocks. 
Nine-tenths  of  the  rocks  on  the  surface  of  the  globe  were 
made  prior  to  this  period.  Many  of  these  beds  during 
this  revolution  were  crystallized,  and  also  stored  with 
mines  of  gold,  tin,  copper,  lead,  etc.,  thus  fitting  them 
for  the  purposes  of  art  and  commerce. 

2 .  ^Progress  of  .Life .  — We  have  beheld  seas — vast 
watery    deserts — become   densely    populated.    We    have 
traced  the   Creative    thought    slowly   advancing  among 
the  ruins  of  ages.      The   five  types  of    structure   have 
all  been  introduced,  and  all,  except  the  vertebrate,  devel- 
oped to  their  higher  orders.     The  lower  forms  have,  one 
ay  one,  given  place  to  the  higher.     We  now  pass  over  a 
chasm  to  where  the  distinctions  stand  out  in  bold  relief. 
We  take  leave  of  the  trilobites,  graptolites,  orthoceratites, 
eurypteri  and  corals  of  the   Silurian   seas,  of  the   mail- 
encased  fishes  of  the  Old  Red   Sandstone,  of  the   sigil- 
lariae,  stigmariae,  and  lepidodendra  of  the  Carboniferous 
jungles,   and  go  forward  to  meet   higher   forms   of  life 
more  nearly  resembling  those  of  the  present  age.    The 
Paleozoic  types  fade  away  in  the  world's  progress  to  its 
brighter  future.    "As  the  stars  sink,  one  by  one,  in  the 
west,  and  new  stars  rise  in  the  east,  to  be  succeeded  by 
the  dawn  and  then  the  day,  so  through  the  night  of  the 
past  sank  the  old  life-forms,  to  be  succeeded  by  the  new, 
approaching  nearer  to   the   dawn  of  the  day  in   whose 
morning  we  live."    (Denton.) 


166  THE    AGE    OF  HEP  TIL  £8. 


fHE    HESOZOIC    |IME. 

The  Mesozoic  or  Middle-life  of  Geologic  History  com. 
prises  but  one  age,  that  of  reptiles. 

[  3.  Cretaceous  Period. 

THE  AGE  OF  REPTILES.    -J  2.  Jurassic  Period. 

(  i.  Triassic  Period. 

General  CJiaraclerislics .  —  A  new  cycle  now 
begins.*  The  five  grand  old  types  of  life  remain,  but 
they  are  to  be  presented  under  new  and  more  familiar 
features.  The  four  orders  of  vertebrates  are  at  last  to 
be  completed.  The  air  becoming  purified  for  land 
animals,  a  flora  arises  capable  of  supporting  a  more 
abundant  fauna.  Birds,  mammals,  common  or  bony 
fishes,  palms  and  flowering  plants  are  to  appear.  The 
Paleozoic  plants  expanded  and  made  their  develop- 
ment mainly  in  the  sculptured  stem;  the  Mesozoic, 
in  the  beauty  of  fruit  and  flower.  The  Paleozoic  corals 
had  rays  or  arms  arranged  in  fours',  the  later  corals, 
in  sixes.  The  Paleozoic  chambered  shells  had  plain 
and  simple  divisions;  the  later  shells  have  intricately- 


*  The  "  differentiation,"  as  it  is  called,  of  the  vital  functions  now  became 
more  marked,  i.  e.,  instead  of  organizations,  in  which  several  functions  are  per- 
formed by  the  same  organ,  each  function  has  an  organ  specially  devoted  to  its 
use.  There  was  also  a  progress  in  "  Cephalization,"  or  head-development.  Ex- 
ternal characteristics  appeared,  which  are  so  apparent  that  "  if  the  Paleozoic  and 
Mesozoic  fossils  were  arranged  on  opposite  sides  of  a  museum,"  says  Page, 
"  the  difference  would  strike  an  observer  as  would  that  between  the  brute-man 
sculptures  of  Nineveh  and  the  man-god  of  the  Greeks  and  Komans." 


TRIASStC    ANti    JURASSIC    PERIODS.     167 

folded  ones.  The  Paleozoic  fishes  had  tails  unequally 
lobed ;  since  then,  the  equally-lobed  or  undivided  tail  has 
been  the  usual  form.  Aside  from  these  general  features, 
the  distinguishing  characteristic  of  the  Mesozoic  Time  is 
the  extraordinary  development  of  reptiles.  These  ani- 
mals astonish  us  by  their  vast  number,  gigantic  size,  and 
unwonted  appearance.  Through  those  antique  forests 
enormous  lizards,  forty  to  fifty  feet  in  length,  dragged 
their  ponderous  bodies, — the  modern  representatives  of 
which  are  inoffensive  little  creatures  a  few  inches  long, 
that  seek  only  to  hide  from  our  view  in  the  grass. 

Geography. — The  continent  has  grown  by  the 
addition  of  the  Carboniferous  area.  The  Appalachian 
region  has  been  uplifted  above  the  sea.  The  scene  of 
rock-making  is  pushed  to  the  borders  of  the  Atlantic  and 
the  Gulf,  and  to  the  slopes  of  the  Eocky  Mountains.  The 
accompanying  map  is  an  attempt  to  show  some  of  the 
outlines  of  the  Mesozoic  continent.  New  England  was  a 
peninsula.  The  beautiful  valley  of  the  Connecticut  was 
an  arm  of  the  ocean,  with  broad,  flat,  muddy  shores. 
The  Gulf  States  were  out  afc  sea.  The  Gulf  of  Mexico 
swept  along  the  eastern  flank  of  the  yet  emerging  Eocky 
Mountains  to  the  Arctic  Ocean,  while  the  Pacific  Ocean 
washed  the  site  of  the  future  Sierra  Nevada.  New  Jersey, 
Maryland,  Delaware,  North  and  South  Carolina,  were  as 
yet  only  half  made.  (See  Fig.  72.) 

TRIASSIC    AND    JURASSIC    PERIODS. 

These  groups  are  not  fully  separated  in  America.  The 
Triassic  (triple)  takes  it  name  from  the  fact  that,  in  Ger- 


168 


THE     AGE      OP     REPTILES. 


many  it  is  composed  of  three  distinct  groups.*  It  is 
sometimes  termed  the  New  Red  Sandstone,  to  distinguish 
it  from  the  Old  Red  Sandstone  of  the  Devonian.  The 
Jurassic  is  so  called  because  it  is  extensively  developed  in 
the  Jura  Mountains,  Switzerland.  The  foreign  divisions 
are  the  Lias,  Oolite,  and  Wealden. 


The  Mesozoic  Cont 


Z,ocation.  —  lK  the  United  States  the  rocks  of  this 
period  are  found    along   the   Connecticut  Valley   from 

*  The  Bunter  Sandstein  or  colored  sandstone,  the  Muschelkalk  or  mussel 
chalk,  and  the  Keuper,  a  miner's  term,  meaning  a  group  of  red  and  green  marls 
and  shell  H. 


TRIASSIC    AND     JURASSIC    PERIODS.    169 

Long  Island  Sound  to  the  northern  boundary  of  Massa- 
chusetts ;  thence  they  may  be  traced  from  the  Palisades 
on  the  Hudson,  in  long,  narrow,  scattered  strips  through 
New  Jersey,  Pennsylvania,  Virginia,  and  North  Carolina. 
(See  Frontispiece.)  They  probably  occupy  the  synclinal 
valleys  running  north  and  south,  left  between  the  great 
folds  of  the  Appalachian  Eevolution.  During  that  time 
they  were  under  the  water,  and  formed  deep  inland  bays, 
receiving  the  washings  from  adjacent  hills  to  work  into 
rock  formations.  The  beds  are  from  3,000  to  6,000 
feet  thick;  hence  these  valleys  must  have  constantly  set- 
tled and  as  steadily  filled  with  the  accumulating  sedi- 
ment. The  great  Pacific  Triassic  belt  extends  from 
Mexico  to  British  Columbia,  through  a  width  of  per- 
haps four  degrees  of  longitude  (Whitney).  The  rocks 
are  also  found  extensively  in  Colorado  and  Nevada. 

J^inds  of  ffiocfc. —  The  rocks  of  the  Connecticut 
valley  are  principally  sandstones,  which  are  extensively 
quarried  for  the  "  brown-stone  fronts  "  of  New  York  city. 
The  popular  "  free-stone "  of  Portland,  Conn.,  and  New- 
ark, N.  J.,  is  a  Triassic  rock.  Near  Eichmond,  Va.,  and 
Deep  River,  N.  C.,  are  valuable  coal  beds  in  the  rocks  of 
this  era.  At  the  west  this  formation  consists  of  beds  of 
brick-red  marl  and  sandstone.  The  celebrated  Solen- 
hofen  limestone,  so  much  used  in  lithography,  is  of  the 
Jurassic  Period. 

Fossils.  —The  organic  remains  are  of  the  most  varied 
and  wonderful  description.  They  reveal  very  clearly  the 
plant  and  animal  life  of  these  periods. 

I.  PLAKTS. — The  vegetation  included  numerous  varie- 


110 


THE  AGE     OP    REPTILES. 


ties  of  ferns,  conifers,  and  calamites,  which  formed 
graceful  forests,  as  in  the  Carboniferous  Period;  but 
there  were  no  jungles  of  lepidodendra  or  sigillarise.  In- 
stead of  these,  the  Cycad  appeared.  This  had  a  short 
trunk,  and  at  the  top  a  tuft  of  branching  leaves  (Fig.  82, 
left  of  the  center).  In  shape,  the  leaves  resembled  those 
of  the  palm,  but  did  not  split  lengthwise,  while  they 
unrolled  from  a  coil,  like  those  of  the  fern.  The  struc- 
ture of  the  wood  and  fruit  was  like  that  of  the  conifers. 
The  cycad,  combining  thus  characteristics  of  three  orders 
of  plants — conifers,  ferns,  and  palms — is  another  illus- 
tration of  what  we  have  termed  a  comprehensive  type. 

II.  ANIMALS. — Birds  and  mammals  make  their  first 
appearance,  completing  the  last  and  highest  order  of 
animals.  Spiders,  beetles  and  other  insects  have  been 
discovered,  and  even  their  tracks  in  the  soft  mud  have 
been  preserved.  Fish  remains  are  plentiful,  as  at  Sun- 


FIG.  73. 


FIG.  74. 


Ostrea  Marshii.  Middle  O51ite. 


Trails   ot   Insects  and  Prints  of 
Rain-drops. 


derland,  Mass.    Fig.  73  represents  an  Oolitic  oyster,  the 
progenitor  of  our  modern  bivalve.      Marine   life   seems 


TRIASSIC    AND    JURASSIC    PERIODS.    171 

wanting  in  this  country,  but  the  European  rocks  contain 
a  prolific  record  of  the  Mesozoic  seas.  Crinoids  were 
abundant ;  one  of  these,  the  Lily  Encrinite,  is  especially 
beautiful  (Fig.  75)0  The  cephalopods  reached  their  cul- 
mination in  the  ammonite  and  belemnite. 
FIG.  75- 


Encrinus  (krinon,  a  lily)  liliiformis. 

The  Ammonite  is  the  fully  coiled  and  perfected  or- 
thoceratite  of  the  Silurian  seas.  It  derives  its  name  from 
its  resemblance  to  the  horn  which  decorated  the  front 
of  the  temple  of  Jupiter  Ammon  and  the  bas-reliefs  and 
statues  of  that  pagan  deity.  It  is  found  of  all  sizes,  from 
that  of  a  pin's-head  to  a  cart-wheel.  The  shell  is  thin, 
but  strengthened  by  many  sinuous  partitions  (septa), 
which  add  to  its  beauty  and  strength.*  This  curious 
internal  archwork,  by  its  joinings  with  the  external  shell, 

*  The  economy  of  the  Ammonite  designed  it  to  live  mainly  at  the  bottom  of 
deep  waters,  but  to  be  able  to  rise  at  pleasure  to  the  surface.  For  this  purpose 
the  outer  chamber  (o  o)  (Fig.  76)  of  the  wreathed  shell  was  fitted  for  the  reception 
of  the  animal,  while  the  interior  chambers  (i  i)  were  hollow,  so  as  to  make  the 
whole  structure  nearly  of  the  same  weight  as  the  element  in  which  it  moved. 
Through  all  of  these  chambers  an  elastic  tube  passed  by  means  of  a  pipe  or 
siphuncle  (s  s),  the  tube  being  in  connection  with  the  cavity  of  the  heart,  which, 
under  ordinary  circumstances,  was  filled  with  a  dense  fluid.  When  alarmed,  or 
wishing  to  descend,  the  animal  withdrew  itself  within  the  outer  chamber,  and 
the  pressure  upon  the  cavity  of  the  heart  forced  the  fluid  into  the  siphuncle,  so 
as  to  increase  the  gravity  of  the  shell,  by  which  means  it  readily  sunk  to  the 
bottom.  On  the  other  hand,  when  wishing  to  ascend,  it  had  only  to  project  its 
arms,  and  the  fluid,  being  freed  from  the  pressure,  returned  from  the  siphuncle 
to  the  cavity  of  the  heart,  thus  restoring  the  whole  structure  to  its  ordinary 
floating  gravity.  As  the  pressure  of  water  at  the  sea-bottom  would  break  any 
ordinary  shell,  we  perceive  that  the  septa  were  essential  to  the  preservation  of 
the  little  animal,  enabling  it  to  resist  a  weight  which  would  otherwise  crush  it 


172 


THE    AGE     OF    ItEPTILES. 


adorns  it  with  graceful  figures  resembling  the  most  deli- 
cate foliage  or  embroidery.  The  chambers  are  often 
found  lined  with  quartz  crystals,  making  tiny  geodes  of 

FIGS.  76-7. 


.  ^^^ 

i.  Ammonites  obtusus ;  2.  Section  of  Ammonites  obtusus,  showing  the  interior  cham- 
bers and  siphuncle  ;  3.  Ammonites  nodosus. 

exquisite  beauty,  while  the  edges  of  the  partitions,  being 
converted  into  iron  pyrites,  form  a  kind  of  golden  tra- 
cery, glittering  in  the  midst  of  the  pellucid  spar.  The 
only  surviving  member  of  this  family  is  the  modern 
nautilus  (naus,  a  ship),  the  "fairy  sailor"  of  the  Indian 
seas. 

The  Belemnite  (Memnon,  a  dart)  is  so  called  from  the 
peculiar  shape  of  its  fossils  (Fig.  78).     They  have   also 

FIG.  78. 
||$^ 


••#•  f 


:&', 


Belemnitella  mucronata,  Cretaceous  Period,  N.  J. 

been  vulgarly  called  "  thunder-heads,"  "  lady-fingers,"  etc. 
The  relics  do  not  give  any  idea  of  the  animal  to  which 
the  name  was  applied.  They  were  merely  the  terminal 
bones  of  the  body  and  were  surrounded  with  flesh.  The 


TRIASSIC    AND    JURASSIC    PERIODS.      173 


FIG.  79. 


animal  resembled  the  modern  cuttle-fish.*  It  secreted 
a  kind  of  ink  which  it  used  as  a  means  of  defence. 
In  an  emergency,  it  blackened  the 
water  in  its  vicinity,  and  escaped 
from  sight.  These  ink-bags  have 
been  found  so  perfectly  preserved 
that  their  contents  have  been  used 
in  sketching  their  fossil  remains. 

The  enormous  reptiles  are,  how- 
ever, the  distinguishing  fossils  of  the 
age.  We  shall  notice  only  the  more 
prominent  ones. 

1.  The  Ichthyosaur  (fish-lizard)  is 
a  striking  illustration  of  a  compre- 
hensive type,  having  the  general  con- 
tour of  a  dolphin,  the  snout  of  a 
porpoise,  the  head  of  a  lizard,  the 
jaws  and  teeth  of  a  crocodile,  the 
vertebrae  of  a  fish,  the  sternal  arch 
of  the  water-mole,f  the  paddles  of 
a  whale,  and  the  trunk  and  tail  of 
a  quadruped.  Its  habits  were  doubt- 
less aquatic,  while,  like  the  whale, 

.,    ,  ,11  T  .  Belemnite  restored;  a,  the 

it  breathed  atmospheric  air,  and  was         ink-bag  in  place. 

*  All  are  familiar  with  "  cuttle-fish  bones,"  so  commonly  used  as  food  for 
canary  birds.  The  substance,  it  is  well  to  observe,  is  not  a  "bone,"  nor  de- 
rived from  a  true  "  fish."  It  is  simply  the  rudimentary  shell  of  a  mollusk. 
The  cuttle-fish  of  our  own  shores  is  a  harmless  animal,  only  ten  or  twelve 
inches  long,  but  the  one  frequenting  the  African  seas  attains  a  formidable  size. 
This  is  the  "  devil-fish,"  so  graphically  described  by  Victor  Hugo.  Its  staring, 
glassy  eyes  strike  terror  to  beholders.  It  has  eight  huge,  muscular  arms,  many 
times  the  length  of  its  body,  with  which  it  holds  its  prey  in  a  grasp  so  tenacious 
that  the  arms  have  been  severed  before  they  would  yield. 

t  The  ornithorhynchus  or  water-mole  of  New  Holland  is  a  mammalian-furred 
quadruped  with  webbed  feet  and  the  bill  of  a  duck.  In  this  animal  the  Creator 
seems  to  have  repeated  the  curious  contrivance  originally  provided  for  the 
Ichthyosaur.  (See  Fourteen  Weeks  in  Zoology,  p.  109.) 


THE     AGE      OF     REPTILES. 

thus  compelled  to  come  frequently  to  the  surface  of 
the  water.  Its  neck  was  short  and  thick,  its  head 
large,  and  its  body  twenty  or  thirty  feet  long.  Its 
jaws  had  an  enormous  opening,  some  having  been 
found  with  160  teeth,  which  could  be  renewed  many 
times,  as  above  each  tooth  was  always  the  bony  germ 
of  a  new  one.  The  eyes  were  often  two  feet  in  diam- 
eter. Surrounding  the  pupil  of  each  one  was  a  circu- 
lar series  of  thin  bony  plates.  This  apparatus,  which 
still  exists  in  the  eyes  of  turtles  and  lizards,  could  be 
used  to  increase  or  diminish  the  curvature  of  the  cornea, 
and  adapt  the  magnifying  power  to  the  wants  of  the 
animal.  The  eye  could  thus  be  used  as  a  telescope  or 
a  microscope  to  see  its  prey  far  and  near,  and  to  descry 
it  in  the  darkness  and  depths  of  the  sea.  The  fossil  ex- 
crements of  the  Ichthyosaur  are  styled  coprolites,  and 
when  polished  are  sold  as  jewelry.*  They  reveal  dis- 
tinctly the  food  and  the  internal  organism  of  this  Meso- 
zoic  saurian.  In  them  have  been  found  the  scales  and 
bones  of  smaller  animals  of  their  own  species.  The  quar- 
ries of  Lyme  Regis,  in  Dorsetshire,  England,  abound  in 
the  remains  of  the  Ichthyosaur. f 


*  Under  the  name  of  "beetle  stones"  coprolites  have  also  been  used  for 
artistic  purposes.  Dr.  Buckland,  the  celebrated  English  geologist,  had  a  table 
in  his  drawing-room  that  was  made  entirely  of  these  fossils,  and  was  often  much 
admired  by  persons  who  had  not  the  least  idea  of  what  they  were  looking  at. 
"I  have  seen,"  says  his  son,  "in  actual  use,  ear-rings  made  of  the  polished 
portions  of  coprolites  (for  they  are  as  hard  as  marble) ;  and  while  admiring 
the  beauty  of  the  wearer,  have  made  out  distinctly  the  scales  and  bones  of  the 
dsh  which  once  formed  the  dinner  of  a  hideous  reptile,  but  now  hung  pendulous 
from  the  ears  of  an  unconscious  belle,  who  had  evidently  never  read  or  heard  of 
such  productions."— Buckland1  s  Curiosities  of  Natural  History. 

t  In  1811,  Mary  Anning,  a  poor  country  girl,  who  made  her  precarious  living 
by  picking  up  fossils,  for  which  the  neighborhood  was  famous,  was  pursuing 
her  avocation,  hammer  in  hand,  when  ehe  perceived  some  bones  projecting  a 
little  out  of  the  cliff.  Finding,  on  examination,  that  it  was  part  of  a  large  skele- 


••••P1 


TRIASSIC    AND     JURASSIC    PERIODS.     177 

2.  The  Plesiosaur  had  the  head  of  a  lizard,  the  teeth  of 
a  crocodile,  the  neck  of  a  swan,  the  trunk  and  tail  of  a 
quadruped,  the  ribs  of  a  chameleon,*  and  the  paddles  of 

FIG.  81. 


A  Coprolite. 


ton,  she  cleared  away  the  rubbish,  and  found  the  whole  creature  imbedded  in 
the  block  of  stone.  She  hired  workmen  to  dig  out  the  block  of  lias  in  which  it 
was  buried.  In  this  manner  was  the  first  of  these  monsters  brought  to  light ;  a 
monster  some  thirty  feet  long,  with  jaws  nearly  a  fathom  in  length,  and  huge 
saucer  eyes— which  have  since  been  found  so  perfect  that  the  petrified  lenses 
have  been  split  off  and  used  as  magnifiers. 

Hugh  Miller  gives  the  following  graphic  description  of  the  lias  of  Scotland : 
"It  consists  of  laminae  as  thin  as  sheets  of  pasteboard,  which,  of  course,  shows 
that  there  was  but  little  deposited  at  a  time,  and  pauses  between  each  deposit. 
Yet  never  did  characters  or  figures  lie  closer  on  a  printed  page  than  the  organ- 
isms on  the  surfaces  of  these  leaf-like  laminae.  We  insinuate  our  lever  into  a 
fissure,  and  turn  up  a  portion  of  one  of  the  laminae,  whose  surface  had  last  seen 
the  light  when  existing  as  part  of  the  bottom  of  the  old  Liassic  sea,  when  more 
than  half  of  the  formation  had  still  to  be  deposited.  The  ground  of  the  tablet  is 
of  a  deep  black,  while  the  colors  of  the  fossils  stand  out  in  various  shades,  from 
opaque  to  a  silvery  white  or  deep  gray.  There,  for  instance,  is  a  group  of  large 
ammonites,  as  if  drawn  in  white  chalk ;  there,  a  cluster  of  minute  bivalve 
shells,  each  of  which  bears  its  thin  film  of  silvery  nacre.  We  turn  over  another 
page.  Here  are  ammonites  of  various  sizes,  but  all  of  one  species,  as  if  a  whole 
argosy  had  been  wrecked  at  once  and  sent  to  the  bottom.  And  here  we  open 
yet  another  page,  which  bears  a  set  of  extremely  slender  belemnites.  They  lie 
along  and  athwart,  and  in  every  possible  angle,  fike  a  heap  of  boarding-pikes 
thrown  carelessly  down  a  vessel's  deck  on  the  surrender  of  her  crew.  Here,  too, 
is  an  assemblage  of  bright,  black  plates,  that  shine  like  pieces  of  Japan  work, 
the  head-plates  of  some  fish  of  the  ganoid  order ;  and  here  an  immense  accumu- 
lation of  minute,  glittering  scales  of  a  circular  form.  And  so,  leaf  after  leaf,  for 
tens  and  hundreds  of  feet  together,  repeats  the  same  strange  story.  The  great 
Alexandrian  Library,  with  its  unsummed  tomes  of  ancient  literature,  the  accu- 
mulation of  long  ages,  was  but  a  poor  and  meager  collection,  scarce  less  puny  in 
bulk  than  recent  in  date,  when  compared  with  this  vast  and  wondrous  library  of 
the  lias  of  Scotland." 

*  Each  pair  of  ribs  surrounded  the  body  with  a  complete  girdle  formed  of  five 
pieces,  thus  affording  great  facility  for  the  expansion  and  dilation  of  the  lungs. 


178  THE     AGE     OF    REPTILES. 

a  whale.  Its  tail  was  shorter  than  that  of  the  iclithy- 
osaur,  being  only  sufficient  to  act  as  a  rudder  in  guiding 
the  body.  To  compensate  this  loss  and  assist  in  propul- 
sion, its  paddles  were  much  larger  and  more  powerful. 
Its  appearance  presented  a  striking  contrast  to  that  of  its 
more  ponderous  foe,  the  ichthyosaur,  whose  attacks  it 
could  escape  by  sinking  to  the  bottom,  while  its  long 
neck  reached  to  the  surface  of  the  water  and  maintained 
respiration. 

3.  The  Pterodactyle  (wing-fingered),  in  its  apparent 
monstrosity*  surpassed  even  the  two  reptiles  just  men- 
tioned. It  was  so  named  because  the  bone  of  one  finger 
was  greatly  expanded  in  order  to  support  an  extended 
membrane  for  flying  (Fig.  82).  It  was  a  true  aerial 
reptile.  Its  wings  resembled  those  of  bats.  Its  bones 
were  hollow,  like  those  of  birds,  but  it  bore  no  feathers, 
and  had  a  mouth  full  of  teeth.  Remains  have  been  found 
indicating  a  spread  of  wing  of  not  less  than  sixteen  feet ; 
but  the  usual  species  of  the  Liassic  did  not  exceed  ten 
inches  in  length.  Its  ordinary  position  was  upon  its 
hind  feet,  walking  uprightly  with  folded  wings,  or 
perched  on  trees,  or  climbing  along  cliffs  with  its  hooked 


*  The  fins  of  the  fishes  of  the  Devonian  seas  became  the  paddles  of  the  ichthy- 
osaur and  of  the  plesiosaur ;  these,  in  their  turn,  became  the  membranous  foot 
of  the  pterodactyle,  and,  finally,  the  wing  of  the  bird.  Afterwards  came  the 
articulated  fore-foot  of  the  terrestrial  mammalia,  which,  after  attaining  remark- 
able perfection  in  the  hand  of  the  ape,  became,  finally,  the  arm  and  hand  of  man, 
an  instrument  of  wonderful  delicacy  and  power,  belonging  to  an  enlightened 
being  gifted  with  the  divine  attribute  of  reason  1  A  careful  examination  of  the 
fore  paddles  of  the  plesiosaur  reveals  all  the  essential  parts  of  the  human  arm— 
the  scapula,  humerus,  radius  and  ulna,  the  bones  of  the  carpus,  the  metacarpus 
and  the  phalanges.  Was  not  this  a  prophecy  of  man?  "Let  us,  then,  dismiss 
this  idea  of  monstrosity,  which  can  only  mislead  us,  and  not  consider  antedilu- 
vian beings  as  mistakes  or  freaks  of  nature.  Let  us  not  regard  them  with  dis- 
gust ;  let  us  learn,  on  the  contrary,  to  behold  in  them  with  admiration  the  divine 
proofs  of  design  which  they  display,  and,  in  their  organization,  to  see  the  handi- 
work of  the  sublime  Creator  of  all  things," 


TRIASSIC   AND    JURASSIC   PERIODS.    181 

slaws  and  feet.  The  smaller  ones  lived  on  insects,  but 
the  larger  probably  pounced  on  struggling  reptiles,  or, 
diving  into  the  water,  preyed  on  fish.  More  than  twenty 
species  of  the  pterodactyle  have  been  discovered  in  the 
old  world,  but  in  the  new  there  have  been  found  only  a 
pair  of  finger-bones,  at  Phoenixville,  Pa.*  Poets  have  long 
pictured  to  us  a  flying  dragon  of  the  olden  time,  which 
played  a  conspicuous  part  in  pagan  mythology.  It 
breathed  fire,  poisoned  the  air  with  its  exhalations,  and 
disputed  with  man  the  possession  of  the  earth.  In  the 
Jurassic  times  we  find  the  realization  of  this  creature 
of  poetic  fancy,  but  it  is  only  an  uncouth  reptile,  utterly 
unworthy  of  those  fabled  conflicts  in  which  gods  and 
heroes  shared. 

4.  The  Dinosaurs  (terrible  lizards)  were  land  reptiles 
of  enormous  size  that  roamed  elephant-like  over  the 
river-plains,  or  browsed  in  the  forests  of  the  Oolitic  and 
Wealden  Epochs.  These  included  the  megalosaur  (large 
lizard),  hylaeosaur  (wood-lizard),  iguanodon,  etc.  (Fig. 
83),  huge  monsters  from  forty  to  seventy  feet  in  length. 
The  megalosaur  was  carnivorous,  having  teeth  curved 
backward  like  a  pruning-knife,  and  with  a  double  edge 
of  enamel  so  as  to  cut  like  a  sabre  equally  on  each  side. 
The  iguanodonf  (ig-wan-o-don)  was  herbivorous,  twigs  of 
cypress  having  been  found  fossil  in  its  stomach,  and 
its  teeth  often  being  half-worn  to  the  roots. 

*  The  pterosaurs  (pterodactyls)  or  flying  lizards,  found  by  Marsh  in  the  creta- 
ceous rocks  of  Kansas,  had  toothless  jaivs  sheathed  with  horn,  as  in  birds,  and 
some  possessed  a  wing-expanse  of  25  feet. 

t  A  party  of  twenty-one  scientific  men,  at  the  invitation  of  Dr.  Hawkins, 
once  took  dinner  within  the  restored  body  of  this  animal.  On  that  occasion 
Dr.  Owen,  the  celebrated  geologist,  sat  in  the  head  for  brains !  This  model 
contains  650  bushels  of  artificial  stone,  100  feet  of  iron  hooping,  600  bricks,  20 
feet  of  inch  bar  iron,  900  plain  tiles,  and  650  two-inch,  half-round  drain  tiles  ; 
while  the  legs  are  four  iron  columns,  nine  feet  long  and  four  inches  in  diam- 
eter. ("  Penny  Guide  to  the  Crystal  Palace  at  Sydenham.") 


182  TEE     AGE     OF     REPTILES. 

FIG.  83. 


The  Megalosaur  and  Hylaeosaur.    Restored  by  Hawkins. 

There  is  a  restoration  of  a  megalosaur  in  the  Crystal 
Palace  at  Sydenham,  England.  This  model  was  con- 
structed under  the  direction  of  B.  Waterhouse  Hawkins. 
On  the  back  of  the  animal  is  a  hump  like  the  withers 
of  a  horse.  (See  p.  269.)  From  the  few  bones  discov- 
ered at  that  time,  this  celebrated  anatomist  decided  that, 
to  make  the  huge  head  effective,  a  mass  of  muscle  and 
bone  on  the  fore  shoulders  was  essential.  This  bunch 
was  thought  by  other  geologists  to  be  a  mere  monstrosity 
of  his  own  invention.  Subsequently,  the  dorsal  vertebrae 
being  found,  the  conclusion  was  proved  to  be  correct. 

5.  The  Labyrinthodon  was  a  frog-like  quadruped,  often 
attaining  the  size  of  an  ox.  It  is  so  named  because  the 
outer  coating  of  its  teeth  was  bent  inward  in  intricate 
mazy  folds.  Its  head  was  protected  by  a  helmet,  and  its 
body  by  a  scaly  armor. 

The  Ramphorhyncus,  the  remains  of  which  have 
been  found  in  the  quarries  of  Solenhofen,  is  a  curious 
intermediate  link  between  birds  and  reptiles.  Its  tail, 


TRIASSIC    AND    JURASSIC    PERIODS.      183 

a  singular  appendage   shown   in   the   figure,  was   long, 
reptile-like,  and  dragged  upon  the  ground,  while  its  foot- 

FIG.  84. 


Labyrinthodon  of  the  Trias  restored,  with  its  foot-prints. 

prints  were  bird-like.  Stranger  still,  the  Kansas  rocks  of 
the  next  period  have  afforded  Marsh  remains  of  a  bird 
with  its  mouth  full  of  teeth  set  in  sockets. 

FIG.  85. 


The  Ramphorhyncus,  with  OOlitic  Vegetation. 


184 


THE     AGE     OF     REPTILES. 


Bird-tracks •-  --In  the  red  sandstones  of  the  Connecticut 
valley,  numerous  foot-prints  have  been  found,  described 

FIG.  86. 


Imprints  of  Feet,  Turner's  Falls,  Massachusetts. 


TRIASSIC    AND    JURASSIC    PERIODS.     185 

by  Hitchcock  as  mainly  the  tracks  of  birds.  The 
number  of  these  foot-prints  is  wonderful.  Tracks  of 
many  different  sizes  and  species  often  traverse  the  same 
slab.  The  largest  tracks  are  fifteen  inches  long,  and 
so  deep  as  to  hold  nearly  two  quarts  of  water.  They 
were  made  by  an  animal  walking  erect  and  having  a 
stride  of  three  feet.  Hitchcock  estimates  that  it  far  ex- 
ceeded the  ostrich  in  size,  being  at  least  twelve  feet  high, 
and  weighing  from  400  to  800  pounds.  From  the  fact 
that  parallel  rows  of  tracks  are  found,  we  infer  that  these 
strange  bipeds  frequented  in  flocks  the  shores  of  the  Con- 
necticut, and  waded  into  its  shallow  waters  in  quest  of 
the  fish  and  mollusks  of  the  Mesozoic  types,  now  long 
extinct.*  Geologists  are  divided  in  opinion  ay  to  whether 
any  of  these  tracks  were  made  by  birds,  and  not  rather 
by  three-  toed  reptiles  somewhat  similar  to  the  ramphor- 
hyncus.  (Fig.  85.) 


.—  /.  Ctimate.—The  Gulf  Stream,  sweep- 
ing northward  through  the  center  of  the  continent, 
combined  with  the  other  causes  already  named  to 
ameliorate  the  climate  so  as  to  permit  a  sub-tropical 
growth  as  far  north  as  latitude  60°.  Corals  and  ammo- 
nites, now  restricted  to  torrid  seas,  then  flourished  in  the 


*  u  It  is  a  solemn  and  impressive  thought  that  the  footprints  ol  these  dumb  and 
senseless  creatures  have  been  preserved  in  all  their  perfection  for  thousands  of 
ages,  while  so  many  of  the  works  of  man  which  date  but  a  century  back  have 
been  obliterated  from  the  records  of  time.  Kings  and  conquerors  have  marched 
at  the  head  of  armies  across  continents,  and  piled  up  aggregates  of  human  suf- 
fering and  experience  to  the  heavens,  and  all  the  physical  traces  of  their  march 
have  totally  disappeared ;  but  the  solitary  biped  which  stalked  along  the  mar- 
gins of  a  New  England  inlet  before  the  human  race  was  bora,  pressed  footprints 
in  the  soft  and  shifting  sand  which  the  rising  and  sinking  of  the  continent  could 
not  wipe  onV—Winchell. 


186  THE    AGE     OF    REPTILES. 

valley  of  the  Upper  Mississippi,  while  the  prairies  of  Ohio 
and  Illinois  were  green  with  perennial  palms  and  pines. 

2 '.  Salt  Heds. — The  most  extensive  salt  deposits  in 
Europe  are  of  the  Triassic  Period,  and  it  has  hence  been 
sometimes  styled  the  Saliferous  formation.  In  Cheshire, 
England,  are  two  beds  of  rock  salt,  each  nearly  100  feet 
thick.  At  Cardona,  Spain,  is  a  mountain  of  salt  several 
hundred  feet  high.  This  salt  rock  is  pure  as  glass,  and  is 
carved  into  images,  cups,  etc.,  for  sale  to  travelers.  At 
the  base  is  a  brook,  which  in  rainy  seasons  swells  into  a 
river,  and  carries  down  so  much  salt  as  to  destroy  the 
fish.*  The  mines  of  Cracow,  Poland,  have  been  worked 
at  a  depth  of  over  1,000  feet  in  galleries  whose  total 
length  is  500  miles.  At  one  point  is  a  village  with 
streets  and  houses,  and  even  a  chapel  with  altar,  pulpit, 
statues,  etc.,  all  hewn  out  of  the  solid  rock.  The  deposits 
in  the  salt  beds  indicate  that  the  same  conditions  existed 
in  portions  of  Europe  during  the  Triassic  as  in  New 
York  during  the  Salina' Period. 

3 '.   The   Gold-bearing  ftocfcs  of   California 

are  mainly  Jurassic  or  Triassic  metamorphic  sandstones, 
with  interstratified  quartz  containing  gold.  Where  the 
quartz  veins  have  come  to  the  surface  and  weathered,  the 
particles  of  gold  have  been  washed  out,  and  thus  formed 
the  auriferous  sands.  There  are  frequent  dikes  of  trap 
and  outcrops  of  granite.  On  the  crests  of  the  Sierra 
Nevada  these  masses  of  granite  often  assume  a  dome 


*  This  mountain  presents  a  wondrous  beauty  to  the  looker-on  at  sunrise. 
Aside  from  its  graceful  and  majestic  form,  it  seems  to  rise  above  the  river  like  a 
mountain  of  precious  gems,  displaying  the  brilliant  colors  of  the  rainbow. 


THE     CRETACEOUS    PERIOD.  187 

shape,  and  reach  a  height  of  15,000  feet  above  the  sea- 
level. 

£.  disturbances.  —  Long-continued  upheavals  and 
perhaps  even  terrific  convulsions  attended  the  close  of 
this  era,  whereby  such  stupendous  mountain  ranges  as 
the  Sierra  Nevada,  Sierra  Madre,  etc.,  were  lifted  above 
the  interior  sea.  The  trap  rocks  of  Mts.  Holyoke  and 
Tom,  East  and  West  Rocks  near  New  Haven,  Conn., 
the  Palisades  on  the  Hudson,  and  Bergen  Hill  in  New 
Jersey,  are  all  illustrations  of  the  wide  extent  of  the 
igneous  action.  Everywhere  trap  dikes  and  ridges  at- 
tend this  formation.  The  proofs  that  the  trap  was 
thrown  out  in  a  melted  state  are  abundant.  The  adja- 
cent sandstone  has  been  baked  by  the  heat,  the  layers 
uplifted  by  the  escaping  steam,  and  the  fissures  often 
filled  with  crystallized  minerals. 

CRETACEO  US    PERIOD, 


.  —  The  Cretaceous  rocks  occur  on  the  At- 
lantic coast  from  New  York  to  South  Carolina,  along 
the  Gulf  through  Texas,  far  northward  over  the  slopes 
of  the  Rocky  Mountains,  and  along  the  Pacific  coast 
westward  of  the  Sierra  Nevada.  (See  Frontispiece.) 

J£inds  of  ffiocfc.  —  The  name  is  derived  from 
the  Latin  creta,  chalk.  The  famous  white  "Cliffs  of 
Dover"  are  of  this  formation.  On  our  continent 
this  group  contains  no  chalk  except  a  single  bed  in 
western  Kansas.  The  Cretaceous  rocks  are  mostly  sand- 
stone, of  various  colors  —  white,  green  or  red  —  and  often 


188  THE     AGE     OF    REPTILES. 

so  loose  that  they  may  be  rubbed  to  pieces  with  the  hand 
or  dug  with  a  spade.  Beds  of  "green  sand"  are  abundant 
in  New  Jersey.  This 
is  composed  of  small 
rounded  grains,  con- 
sisting mostly  of  sili- 
cate of  iron  and  potash. 
The  peculiar  shape  of 
these  granules  is  prob- 
ably due  to  the  fact 
that  they  are  the  casts 
of  microscopic  shells. 
It  is  termed  marl,  and 
is  extensively  used  for 
fertilizing  purposes.  In 

A  common  Fossil  of  the  Green  Sand— the  Exo- 

western  Texas  are  beds  gyracostata. 

of  cream-colored  lime- 
stone called  "  Chimney  Stone,"  from  its  use  in  building 
chimneys.  When  taken  from  the  quarry,  it  is  soft 
enough  to  hew  with  an  axe  or  smooth  with  a  plane. 
Valuable  mines  of  coal,  (lignite)  *  and  quicksilver  are 
found  in  California. 

Fossils. — If  we  examine  chalk  with  a  powerful  mi- 
croscope we  shall  see  that  it  is  composed  largely  of  the 
minute  shells  of  various  species  of  rhizopods  \  (foraminif- 


*  The  Great  Lignite  Group  of  the  Rocky  Mountains,  heretofore  known  as  the 
Tertiary  coals  (see  p.  198),  are  now  referred  by  some  of  the  best  authorities  to 
the  Cretaceous  Period.  Read  Stevenson's  report  on  the  Geological  Relations  of 
the  Lignitic  Group. 

t  The  imagination  fails  to  conceive  the  countless  millions  of  these  foraminif- 
era  in  all  ages.  In  Nature  nothing  is  small.  She  seems  to  have  delighted  in 
achieving  the  grandest  results  with  the  feeblest  means.  The  history  of  this  ani- 


THE     CRETACEOUS     PERIOD. 


189 


era),  so  tiny  that  their  very  smallness   seems   to   have 
rendered  them  indestructible.      Eighteen    hundred    of 

FIG.  88. 


Chalk  of  Gravesend  (Ehrenberg). 


these  placed  in  a  row  would  occupy  but  an  inch  of 
space.  Schleiden  says  that  the  chalk  on  a  visiting  card 

malcule  is  a  striking  illustration  of  this  truth.  A  handful  of  sand  taken  up  on 
the  sea-shore  is  often  half  composed  of  these  microscopic  shells.  The  Paris 
chalk  contains  them  so  abundantly  that  D'Orbigny  found  58,000  in  a  cubic  inch  of 
the  rock.  Paris  itself  is  built  up  of  these  cast-off  abodes  of  the  tiny  rhizopod. 
The  species  vary  in  different  sections  and  ages.  A  curious  application  of  this 
has  lately  come  to  notice.  Ehrenberg  was  requested  to  assist  in  tracing  the 
robbery  of  a  case  of  wine.  It  had  been  repacked  by  the  criminal  in  sand  differ 
iag  from  that  in  the  original  case.  Ehrenberg,  by  a  microscopic  analysis,  deter- 
mined that  the  sand  was  found  only  on  a  certain  ancient  sea-coast  in  Germany. 
On  this  fact  being  discovered,  the  locality  of  the  crime  was  speedily  found  and 
the  thief  arrested. 


190  THE    AGE     OF    REPTILES. 

is  a  microscopic  cabinet  of  a  hundred  thousand  shells, 
Throughout  the  beds  of  chalk  are  scattered  nodules  of 
flint,  which,  being  broken,  reveal  at  the  center  shells, 
corals,  etc.,  the  nuclei  around  which  the  flint  collected 
oyt  of  the  chalk  before  that  had  consolidated  from  the 
pasty  mass  in  which  it  first  formed  on  the  sea-bottom. 

1)eep-Sea  Soundings  show  that  the  bottom 
of  the  North  Atlantic,  where  not  deeper  than  15,000  feet, 
is  covered  with  a  fine  ooze,  85  per  cent,  of  which  is  com- 
posed of  rhizopod  shells.  This  "  abysmal  mud  "  is  similar 
in  character  to  chalk,  and  some  of  the  shells  as  well  as 
siliceous  sponges  which  it  contains  are  identical  with 
cretaceous  forms.  The  conclusion  is,  therefore,  obvious 
that  the  deep-sea  bed  of  the  mid- Atlantic  has  remained 
submerged  since  the  Mesozoic  Time,  and  a  part  of  the 
Cretaceous  fauna  has  thus  been  preserved  to  the  present 
day  unchanged.  In  this  sense  of  the  phrase  alone,  we 
may  be  said  to  be  now  "living  in  the  Cretaceous  Pe- 
riod." 

THE  AMERICAN  FOSSILS  are  far  removed  from  the 
microscopic  remains  of  the  Old  World.  While  chalk- 
beds  were  accumulating  on  the  deep-sea  bottom  in  Eu- 
rope, the  shallow  waters  on  the  American  shore  teemed 
with  as  busy  and  strange  a  life  as  swarmed  upon  the 
coasts  of  England,  France  or  Germany  during  the  entire 
Mesozoic  Age.  The  Cretaceous  beds  of  New  Jersey  have 
furnished  abundant  reptilian  remains.* 

1.  The  Cimoliasaur  and  the   Elasmosaur  were  huge 


*  We  are  indebted  to  the  untiring  and  skilful  labors  of  Dr.  Cope  and  Dr.  Leidy. 
Of  Philadelphia,  for  the  following  description  of  these  Cretaceous  reptiles. 


THE     CRETACEOUS     PERIOD.  191 

sea-serpents,  twenty-five  to  forty  feet  long,  with  bodies 
larger  than  an  ox,  sharp  teeth,  and  flippers  like  a  whale, 
— the  latter  having  a  flattened  tail,  which  it  used  like  an 
oar  for  sculling. 

2.  The  Mosasaur  was  a  whale-like,  carnivorous  mon- 
ster, shorter  and  stouter  than  the  preceding  reptiles.    Its 
ponderous  bones  are  wrecked  along  the  old  sea-coast,  and 
may  be  seen  on  the  Alabama  river  projecting  from  the 
limestone  cliffs. 

3.  Strapping-turtles,  six  feet  long  and  of  many  varieties, 
lived  in  the  salt  water,  as  the  now  living  species  do  in 
fresh  water. 

4.  Crocodiles  were  exceedingly  abundant.    Three-fourths 
of  all  the  bones  found  in  the  marl-pits  are  those  of  the 
crocodile.     These  creatures  swarmed  along  what  is  now 
the  river-front  of  Philadelphia,  and  peopled  every  pool 
and  lagoon  on  the  ancient  shores  of  Pennsylvania.     Most 
obstinate  combats  must  have  taken  place  between  these 
fierce   crocodiles   and   the  great   snapping-turtles  which 
inhabited  the  same  waters. 

4.  The  Dinosaurs  rivaled  in  size  the  elephants  of  our 
day.  Their  aspect  was  strange  and  portentous;  some 
chiefly  squatted,  some  leaped  on  their  hind  limbs  like  the 
kangaroo,  and  some  stalked  on  erect  legs  like  great  birds, 
with  small  arms  hanging  uselessly  by  their  sides,  as  with 
bony  visage  they  surveyed  land  and  water  from  their 
lofty  elevation.  Two  of  these  saurians  are  noticeable : 

(a.)  The  Hadrosaur  was  a  massive,  herbivorous  reptile 
about  thirty  feet  long.  The  fossil  remains  have  been 
lately  restored  by  Hawkins,  and  are  set  up  in  the  Mu- 
seum of  Natural  Sciences,  Philadelphia.  This  monster 
doubtless  walked  mainly  on  its  hind  legs,  its  knees 


THE     AGE      OF     REPTILES. 

thrown  upward  and  forward,  and  its  huge  tail  trailing 
behind.  Its  expression  was  that  of  a  perpetual  grin,  as 
its  open  mouth  revealed  several  rows  of  shiny  teeth 
with  which  it  cut  the  twigs  on  which  it  fed. 
(b.)  The  Lcelaps  was  a  powerful,  carnivorous  animal, 
and  the  destructive  enemy  of  the  preceding  smaller  rep- 
tiles. A  full-grown  specimen  was  probably  twenty-three 
feet  in  length.  Its  toes  were  long  and  slender  like  those 
of  a  bird  of  prey.  They  were  armed  with  flattened, 
hooked  claws,  ten  to  twelve  inches  long,  and  adapted  to 
grabbing  and  tearing.  Its  teeth  were  curved,  knife- 
shape,  saw-edged,  and  fitted  like  scissors  for  cutting. 
The  tail  was  long,  rounded,  and  strong,  and  capable  of 
striking  a  blow  or  of  throwing  an  enemy  within  reach 
of  the  kick  or  grab  of  the  terrible  hind  leg.  It  could 
leap  like  the  kangaroo,  and  probably  captured  its  prey  by 
a  few  immense  bounds. 

Scenic  Description.— Let  us  picture  to  our- 
selves a  landscape  in  this  Mesozoic  Age.  It  is  an  arm  of 
the  ocean  with  broad,  flat,  muddy  shores,  at  the  bottom 
of  which  is  slowly  gathering  a  sandy  rock.  The  fog  has 
just  lifted,  and  discloses  a  view  of  surpassing  beauty.  On 
either  hand  the  summits  of  the  hills  are  crowned  with 
lordly  pines,  while  the  sloping  land  is  overgrown  with 
palms  and  tropical  trees.  The  shore  is  green  with  ferns 
and  reeds,  whose  tufted  tassels  nod  in  the  gentle  breeze. 
Insects  flit  among  the  flowers  of  lily  and  palm,  while 
birds  chirp  in  the  cycad  groves.  It  is  the  reign  of 
reptiles.  On  every  hand  they  swarm — crawling,  hopping, 
stalking  by  the  shore.  The  water  is  alive  with  them — 
swimming,  diving,  and  filling  the  air  with  an  indescrib- 


THE      CRETACEOUS     PERIOD.  193 

able  din.  All  day  long  enormous  lizards  crawl  through 
the  forests,  crushing  the  reed-like  trees  before  them  in 
their  headlong  course,  or  plunge  into  the  sea,  leaving 
behind  a  broad  wake  like  a  steamer ;  while  others,  more 
fearful  still,  spread  their  wings  and  riot  in  the  air.  Sail- 
ing in  and  out  among  the  shallow  coves  and  bays  of 
the  coast,  the  plesiosaur,  arching  its  long  neck,  eagerly 
watches  a  shoal  of  fish  swimming  near.  But  with  quick 
sharp  strokes  of  its  whale-like  paddles,  the  huge  ichthyo- 
saur  darts  into  view,  and  glares  upon  its  prey  with  its 
great  bulging  eye.  Instantly  the  swan  neck  disappears 
under  the  water,  and  the  plesiosaur  is  hidden  from  its 
rapacious  foe— the  terror  of  the  Mesozoic  seas.  Mighty 
dinosaurs,  rivaling  the  elephant  in  size,  stalk  along  the 
shore  or  squat  on  the  beach  stupidly  gazing  on  the  scene, 
save  when  the  Maps,  with  fearful  bounds,  leaps  among 
their  frightened  herds,  and  tears  them  with  his  eagle- 
claws.  But  night  draws  on  apace.  In  the  dim  recesses 
of  the  woods  the  pterodactyle — that  winged  dragon  so 
terrible  to  behold — sails  slowly  along  on  its  broad,  leath- 
ern wings.  As  the  shadows  deepen,  mighty  sea-ser- 
pents dart  to-and-fro,  battling  with  the  rising  billows; 
that  huge  bloated  frog — the  labyrinthodon — jumps  by 
with  great  ungainly  hops,  while  a  tiny  mammal,*  the 
first  of  its  kind,  flies  frightened  to  the  shelter  of  the 
woods. 


*  This  was  the  Dromatherium  Sylvestre,  the  jaw-bone  of  which  was  discov- 
ered by  Emmons  in  North  Carolina.  It  is  the  only  mammal  yet  known  to  have 
existed  in  America  during  the  Mesozoic  Age.  In  Europe,  two  or  three  insigni- 
ficant ones  of  the  lowest  order  have  been  discovered.  No  true  bird  remains 
have  been  found  on  this  continent,  but  in  the  quarries  of  Solenhofen  they  have 
been  scantily  preserved.  One,  called  the  Arehaeopteryx,  and  Bird  of  Solenr 
hofen.  is  very  clearly  identified,  except  the  head. 


194  THE      AGE      OF     MAMMALS. 

Mesozoic  "Disturbances . —  The  Mesozoic  Time, 
like  the  Palaeozoic,  was  closed  by  mighty  upheavals.  As 
Winchell  beautifully  says :  "  The  ever-shrinking  earth- 
nucleus  necessitated  the  ever-enlarging  wrinkles  of  the 
enveloping  crust ;  the  furrows  must  deepen  and  the  folds 
must  rise."  The  increasing  pressure  of  the  Atlantic  and 
Pacific  oceans  produced  another  upheaval  of  the  land, 
and  another  addition  to  the  growing  continent.  This 
was  probably  not  a  sudden  convulsion,  but  a  long-con^ 
tinued  upward  movement.  By  it,  however,  the  condi- 
tions of  life  were  changed.  All  the  Mesozoic  types  dis- 
appeared—hardly any  species  survived  the  shock.  A  few 
mammals,  birds  and  flowering  plants,  types  prophetic  of 
the  Cenozoic  Time,  had  appeared,  but  they  all  went  down 
in  the  shock. — Another  cycle  of  geologic  history  is  fin- 
ished, another  phase  of  life  has  swept  across  the  slowly- 
forming  world,  culminated  and  broken  on  the  shore  of 
the  past.  The  reign  of  reptiles  is  closed. 


HENOZOIC    |IME. 

The  Cenozoic  or  recent  life  of  geologic  history  com- 
prises only  one  age,  that  of  mammals. 

AGE  OF  MAMMALS,    j2'  Post-Tertiary  Period, 
(i.  Tertiary  Period. 


General  Characteristics.  —  The  more  striking 
scenes  of  life  hitherto  have  been  confined  to  the  water ; 
they  are  now  transferred  to  the  land.  Extensive  bodies 
of  fresh  water  teem  with  fishes  resembling  pickerel, 


THE    AGE     OF    MAMMALS. 


190 


perch,  eels,  etc.  Molluscan  life  takes  on  the  types  of 
modern  times— the  bivalves  increasing  and  the  gastero- 
pods  taking  the  lead.  Insects  throng  every  element — 
earth,  air  and  water.  Birds  are  also  found  in  greater 
numbers.  It  is  emphatically,  however,  the  age  of  mam- 
mals. Quadrupeds  of  enormous  bulk — many  identical 
with  existing  species — occupy  the  land.  The  herbs, 
shrubs  and  trees — the  flowers,  fruits  and  grains — all  that 
can  gladden  the  senses  or  satisfy  the  wants  of  man — 
appear  and  confirm  the  harmony  that  always  exists  be- 
tween organic  and  inorganic  nature. 

FIG.  89. 


Map  of  Tertiary  Period. 


196  THE    AGE     OF    MAMMALS. 

Geography. — The  great  Mesozoic  upheaval  burst 
asunder  the  Gulf  Stream,  which  had  sent  the  warm 
waters  of  the  tropics  to  the  Arctic  Ocean.  On  the  south- 
west it  retired  to  nearly  its  present  limits,  but  a  long  arm 
reached  up  the  Mississippi  valley  to  the  mouth  of  the 
Ohio  river  (Fig.  89).  On  the  north  it  broadened  into 
the  great  Tertiary  Sea  which  extended  through  Nebraska 
and  the  western  part  of  Dacotah.*  The  Pacific  Ocean 
still  held  possession  of  the  western  coast,  while  the 
Atlantic  Ocean  covered  the  southeastern  border  of  the 
continent,  and  the  coral  builders  were  yet  at  work  upon 
Florida. 

TERTIARY    PERIOD. 

4.  Sumter  (S.  C.)  Epoch. 

.  3.  Yorktown  (Va.)  Epoch. 
PERIOD.   \  2_  Alabama  Epoch_ 

i.  Lignitic  Epoch. 

In  Europe,  the  divisions  of  the  Tertiary  Period  are 
Eocene  (recent  dawn),  Miocene  (less  recent),  and  Pliocene 

*  At  the  close  of  the  Mesozoic  Age,  Europe  was  still  far  from  displaying  the 
configuration  which  it  now  presents.  A  map  of  the  period  would  represent  the 
great  basin  of  Paris  (with  the  exception  of  a  zone  of  chalk),  the  whole  of  Switzer- 
land, the  greater  part  of  Spain  and  Italy,  the  whole  of  Belgium,  Holland,  Prussia, 
Hungary,  Wallachia,  and  northern  Eussia,  as  one  vast  sheet  of  water.  A  band 
of  Jurassic  rocks  still  connected  France  and  England  at  Cherbourg.  This  dis- 
appeared at  a  later  period,  and  caused  the  separation  of  the  British  Islands  from 
what  is  now  France. — Figuier. 

t  The  name  Tertiary  is  a  relic  of  early  geological  science.  When  introduced, 
it  was  preceded  in  the  system  of  history  by  Primary  and  Secondary.  The  first 
of  these  terms  was  thrown  out  when  the  crystalline  rocks,  so  called,  were 
proved  to  belong  to  no  particular  age,  though  not  without  an  ineffectual  attempt 
to  substitute  it  for  Paleozoic ;  and  the  second,  after  use  for  a  while  under  a  re- 
stricted  signification,  has  given  way  to  Mesozoic.  Tertiary  holds  its  place 
simply  because  of  the  convenience  of  continuing  an  accepted  name  (Dana). 
The  term  Quaternary,  used  in  connection  with  the  Post-Tertiary  Period,  had  a 
similar  origin. 


THE     TERTIARY    PERIOD.  197 

(more  recent).  On  this  continent  these  terms  do  not 
apply,  and  an  American  classification  has  been  adopted. 
In  the  Pliocene,  most  of  the  species  are  allied  to  existing 
forms;  in  the  Miocene,  fewer  are  thus  related;  and  in 
the  Eocene,  we  recognize  only  the  dawn  of  modern  forms. 
The  Lignitic  and  Alabama  beds  have  been  referred  by 
Dana  and  other  prominent  authorities  to  the  Eocene, 
the  York  town  to  the  Miocene,  and  the  Sumter  to  the 
Pliocene. 


The  Marine  Tertiary  beds  lie  on  the 
Atlantic,  Pacific,  and  Gulf  borders,*  and  extend  up  the 
Mississippi  valley  to  the  mouth  of  the  Ohio  river.  Fresh 
water  Tertiary  beds  occur  on  the  eastern  slopes  of  the 
Rocky  Mountains  and  in  the  upper  Missouri  region. 
There  are  no  great  continental  strata,  as  in  the  Silurian 
Age,  but  rather  such  a  diversity  as  we  find  in  formations 
now  in  progress  on  the  sea-coast,  where  the  beds  often 
change  in  character  within  small  distances.  These 
modern  deposits  give  us  the  key  to  the  ancient  one 
(See  pp.  23  and  29.) 


*"  What  are  known  as  the  Pine  Barrens,  in  the  southern  States,  is  a  belt  of 
country  more  than  1,700  miles  long,  and  often  170  miles  broad,  stretching  from 
Richmond,  along  the  Atlantic  and  Gulf  coasts,  to  beyond  the  western  line  of 
Louisiana,  where  the  soil,  derived  from  the  decomposition  of  the  newest 
member  of  the  Tertiary  series,  is  sandy,  and  where  the  principal  arborescent 
form  is  the  long-leaf  pine.  It  is  emphatically  the  "poor  man's  region."  These 
forests,  while  affording  a  valuable  article  of  lumber,  also  yield  pitch,  tar,  and 
turpentine.  On  the  Pacific  slope  the  Tertiary  rocks,  which  are  referred  to  the 
Miocene  Group,  appear  to  be  coterminous  with  the  Cretaceous.  They  enter  into 
the  frame-work  of  the  Coast  Ranges,  stretching  from  the  Columbia  to  San  Louis 
Bay,  and  probably  to  Cape  St.  Lucas;  and  throughout  the  entire  extent  the 
strata  are  upheaved,  plicated,  and  metamorphosed,  and,  at  frequent  intervale, 
invaded  by  igneous  products.  They  repose  in  horizontal  strata  upon  the  foot- 
hills  of  the  Siorra,  but  are  in  a  disturbed  position  where  they  fold  around 
Shasta'.— Foster's  Mississippi  Valley,  published  by  Messrs.  S.  C.  Griggs  &  (70M 
Chicago. 


19S  THE    AGE    OF 

J£tnds  of  ffiocfc. — The  Tertiary  beds  consist  of 
sand,  clay,  marl,  pebbles,  etc.  Near  Charleston,  S.  C.,  are 
extensive  phosphate  beds,  rich  in  phosphate  of  lime,  and 
mined  as  a  fertilizer.  At  St.  Augustine,  Fla.,  is  a  curious 
rock,  locally  known  as  "coquina,"  composed  of  broken 
shells,  but  cemented  so  as  to  make  a  good  building  stone. 
The  Eocene  of  the  old  world  contains  strata  of  NUAI- 
MULITIC  (nummus,  a  piece  of  money)  limestone  thousands 
of  miles  in  length  and  hundreds  of  feet  in  thickness.  It 
is  so  called  because  it  is  largely  composed  of  a  fossil* 
having  the  shape  of  a  coin.  The  most  noted  Pyramids 
are  built  of  this  stone,  and  wagon-loads  of  the  fossils,  dis- 
integrated by  the  weather,  lie  at  their  base. 

Extensive  beds  of  light  bituminous  coal  (lignite)  are 
found  scattered  from  Pike's  Peak  to  the  Arctic  Ocean, 

across  Vie  treeless  regions 
FIG.  90.  west  of  the  Missouri,  and 

thence  into  Oregon.  The 
wide  distribution  and  con- 
venient locality  of  these 
Tertiary  coals  must  ex- 
ercise a  vast  influence  in 
facilitating  communica- 
(Nummuiites  ataica).  tions  over  the  great  deserts 
of  the  west,  and  can  but 

be   considered  as  a  providential  forecast  of  the  wants 
of  man. 

Fossils.  —  I.  PLANTS. — The  abundance  of  vegetable 
remains  proves  the  land  to  have  been  covered  with  an 
exuberant  flora.  Leaves  of  oak,  maple,  poplar,  hickory, 

*  The  nummullite  is  a  rhizopod,  being  the  giant  of  that  family.    (See  p.  100.) 


THE     tERTIAHY     PERIOD.  199 

cinnamon,  fig,  palm,  and  pine  are  abundant.*  A  leaf  of  a 
fan-palm  has  been  found  on  the  Upper  Missouri,  that, 
when  entire,  was  probably  twelve  feet  across  (Dana). 
Nuts  are  common  in  some  localities,  as  at  Brandon,  Vt. 
In  the  London  basin  a  single  collector  gathered  25,000 
specimens  of  fossil  fruits  representing  five  or  six  hundred 
species.  Many  of  them  were  products  of  aromatic  and 
spice  groves,  such  as  now  flourish  in  Ceylon  and  the  West 
Indies.  The  extensive  deposits  of  diatoms  at  Richmond, 
Va.,  and  Bilin,  Germany,  etc.,  which  have  been  already 
mentioned  (page  48)  are  of  this  period. 

II.  AKIMALS. — Tertiary  shells  of  over  3,000  species  have 
been  found  in  America.  They  have  the  look  and  often- 
times the  freshness  of  modern  specimens,  as  may  be  seen 
in  the  accompanying  cuts  of  Miocene  Gasteropods,  (See 
Fig.  91.)  In  Colorado  and  Utah  are  shales  containing 
insects  so  well  preserved  that  even  the  microscopic  hairs 
of  the  wings  can  oe  detected  (Denton).  The  first  bee 
made  its  appearance  in  the  amber  f  of  the  Eocene,  locked 


*  The  earth  had  already  its  seasons,  its  spring  and  summer,  its  autumn  and 
winter,  its  seed-time  and  harvest,  though  neither  sower  nor  reaper  was  there ; 
the  forests  then,  as  now,  dropped  their  thick  carpet  of  leaves  upon  the  ground  in 
the  autumn,  and  in  many  localities  they  remain  where  they  originally  fell,  with  a 
layer  of  soil  between  the  successive  layers  of  leaves — a  leafy  chronology,  as  it 
were,  by  which  we  read  the  passage  of  the  years  which  divided  these  deposits 
from  each  other.  Where  the  leaves  have  fallen  singly  on  a  clayey  soil  favorable 
far  receiving  such  impressions,  they  have  daguerreotyped  themselves  with  the 
most  wonderful  accuracy ;  and  the  trees  of  the  Tertiaries  are  as  well  known  to 
us  as  are  those  of  our  own  time. — Agassiz  in  Geological  Sketches. 

t  See  Fourteen  Weeks  in  Chemistry,  page  226.  Amber  has  been  found  quite 
abundant  on  the  shores  of  the  Baltic,  washed  out  of  the  lignite  beds  by  the 
waves.  Species  of  coniferous  trees  existed,  from  which  gum  or  resin  flowed, 
and  becoming  fossilized,  amber  was  the  result.  In  flowing  down  the  tree,  in- 
eecte,  spiders,  small  crustaceans,  and  leaves  were  covered ;  and  thus  we  find 
them  preserved  in  the  transparent  amber.  Over  800  species  of  insects,  and  98 
of  trees  and  shrubs  have  been  observed,  besides  numerous  mosses,  fungi,  and 
liverwort.— Denton  in  Our  Planet. 


FIG.  91.    GASTEROPODS  OF  THE  MIOCENE. 


Pvrula  reticulata. 


Cancellaria  reticulata. 


Fusus  exilis. 


FIG.  92.    GASTEROPODS  OF  THE  MIOCENE. 


Murex  globosa.    (Half  natural  size.)  Galeodia  Hodgii. 

FIG.  93.    ECHINODERMS  OF  THE  MIOCENE. 


Rosette,  beneath. 

FIG.  94. 


Gonioclypeus  subangulatus,  E. 

FIG.  95. 


Scutella  Newbernensis,  E. 
The  "  Lone  Star  of  Texas.' 


Echinus  Ruffini. 


THE     AGE     OF     MAMMALS. 


FIG.  96. 


up  hermetically  in  its  gum-like  covering—"  an  embalmed 
corpse  in  a  crystal  coffin/'  as  Hugh  Miller  quaintly  re- 
marks. Broken  wings  of  butterflies 
also  attest  the  presence  of  flowers. 
Ants,  crickets,  grasshoppers,  beetles, 
and  dragon-flies  are  so  numerous  that 
some  kinds  seem  to  have  afforded  food 
to  the  first  mammals  that  appeared. 
Fish  existed  in  great  abundance, 
mostly  allied  to  the  modern  perch 
and  salmon.  Sharks'  teeth  have  been 
found  six  inches  in  length. 

The  bones  of  a  species  of  whale 
called  the  Zeuglodon  (yoke-tooth),  so 
called  from  the  shape  of  its  teeth, 
occur  in  great  abundance  scattered  over  the  cotton  lands 
of  the  south.  In  Alabama  they  have  been  laid  up  in 

FIG.  97. 


Oxyrhina  Desorii. 
Shark's  Tooth  from  N.  C. 


Zeuglodon's  Tooth. 


THE      TERTIARY     PERIOD.  203 

walls  for  fences,  or  burned  for  lime.  A  single  vertebra  is 
a  load  for  a  man  to  carry.  The  animal  was  about 
seventy  feet  long.* 

QUADKUPEDS,  thick-skinned  and  ruminating  mammals, 
were  the  great  feature  of  the  Tertiary  life. 

European  Quadrupeds. — Cuvier  was  the  first  to  bring 
to  light  the  forms  of  these  long-extinct  animals.  In  the 
Gypsum  quarries,  near  Paris,  bones  were  dug  up  in  great 

FIG.  98. 


Scene  in  Paris  Basin. 
i.  The  Paleotherium.     2.  The  Anoplotherium.     3.  The  Xiphodon. 

numbers,  but  they  were  disregarded,  as  they  were  thought 
to  be  those  of  existing  species,  until  the  attention  of  this 
great  naturalist  was  directed  to  them.  He  gathered  a 
large  quantity  in  a  room,  and  commenced  the  work  of 
assorting  and  re-creating.  "At  the  voice  of  comparative 
anatomy  every  bone  and  fragment  resumed  its  place." 


*  The  restored  skeleton  of  a  Zeuglodon  is  on  exhibition  in  Wood's  Museum, 
Chicago.  It  contains  118  vertebrae,  and  its  head  is  six  feet  long.  Prof.  Winchell 
pronounces  it,  for  the  most  part,  an  accurate  representation  of  this  alligator-like 
whale. 


204 


THE     AGE      OF     MAMMALS. 


(Cuvier.)     He  restored   the   animals,  assigned   them  to 
their  classes,  and  investigated  their  habits. 

The  neighborhood  seems  to  have  been  a  gulf  of  the  sea, 
into  which  emptied  several  rivers.  Animals  inhabiting 
the  banks  of  these  streams  were  borne  down,  and  de- 

FIG.  99. 


View  of  the  Bad  Lands. 

posited  in  the  sediment  which  gathered  at  the  mouth. 
Among  the  quadrupeds  the  most  conspicuous  was  the 
Paleotherium  (ancient  wild  beast),  peaceful  flocks  of 
which  must  have  inhabited  the  plateau  which  environed 
the  ancient  basin  of  Paris.  It  resembled  the  South 
American  tapir,  but  was  as  large  as  a  horse. 

American  Quadrupeds. — On  this  continent  similar  dis- 
coveries have  been  made  in  the  Mauvaises  Terres,  or  Bad 
Lands  of  Dacotah.  This  region  consists  of  immense  beds 
of  clay  cut  out  by  rivers  into  winding  channels,  leaving 


TH  E      TERTIARY     PERIOD.  205 

thousands  of  irregular  columnar  masses  often  one  to  two 
hundred  feet  in  height.  So  thickly  is  the  surface  studded 
with  these  natural  towers,  that  the  traveler  must  thread 
his  way  through  deep,  confined  labyrinthine  passages  not 
unlike  the  narrow,  irregular  streets  and  lanes  of  some 
quaint  old  European  town.*  The  soil  is  barren  and  arid. 
It  is  a  literal  Golgotha — a  place  of  bones.  At  every  step 
in  this  charnel-house  the  explorer  treads  upon  the  re- 
mains of  a  former  age.  The  clayey  walls  are  built  up 
with  broken  skeletons.  Hundreds  of  fossil  turtles  (see 
Fig.  100)  are  strewn  about,  many  weighing  a  ton  each. 
On  every  side  are  scattered  bones  strangely  like  the 
familiar  forms  of  to-day,  but  of  unknown  species  and 
unwonted  combinations.  Thus  the  Titanothere  was 
tapir-like,  but  had  horns  and  was  8  feet  high.  The  Din- 
oceras  resembled  an  elephant  in  size,  but  instead  of  a 
trunk  had  three  pairs  of  horns. 

The  Origin  of  this  Region  was,  probably,  as  fol- 
lows :  The  great  Tertiary  sea  was  at  first  salt,  but  receiv- 


*  These  rocky  piles,  in  their  endless  siiccession,  assume  the  appearance  of 
massive  artificial  structures  decked  out  with  all  the  accessories  of  buttress  and 
turret,  arched  doorway  and  clustered  shaft,  pinnacle  and  finial  and  tapering 
spire.  On  a  nearer  approach  the  illusion  vanishes,  and  all  the  forms  which  fancy 
has  conjured  are  resolved  into  barren  desolation.  The  bottom  of  the  vale  is  an 
earth  of  chalky  whiteness,  baked  by  the  sun,  and  utterly  destitute  of  vegetation. 
The  water  which  oozes  out  of  the  foundation-wall  of  the  prairie  is  brackish  and 
unpalatable.  In  winter,  the  wind  and  snow  rush  through  the  lanes  and  corri- 
dors of  this  city  of  the  dead  in  eddying  whirls,  while  the  withered  grasses  and 
the  voiceless  and  motionless  solitude,  together  with  the  relentless  frost  and 
never-tiring  storm,  make  the  place  the  realization  of  utter  bleakness  and  desola- 
tion. In  summer  the  scorching  sun  literally  bakes  the  clays  which  have  been 
kneaded  by  the  frosts  and  thaws  of  spring ;  and  the  daring  explorer  of  the  scene 
finds  no  tree  nor  shrub  to  shelter  him  from  the  fervid  rays  poured  down  from 
above,  and  reflected  from  the  white  walls  which  tower  around  him,  and  the 
whHe  floor  which  almost  blisters  his  feet  —  Sketches  of  Creation  —  Wlnchett. 


THE    AGE    OF   MAMMALS. 

ing  fresh  water  from  the  drainage  of  the  adjacent  land, 
and  having  an  outlet  into  the  ocean,  it  gradually  became 
a  brackish,  and  at  last  a  fresh-water  sea.  As  the  conti- 
nent was  elevated,  this  great  inland  sea  was  drained  in 
part,  and  in  time  probably  became  broken  up  into  a 

FIG.  ioo. 


Testudo  Oweni. 


chain  of  fresh-water  lakes.*  The  basin  of  one  of  these, 
now  constituting  the  Bad  Lands,  is  thought  by  Hay  den 
to  have  covered  an  area  of  150,000  square  miles— five 
times  as  great  as  that  of  Lake  Superior.  The  shores  of 
these  lakes  during  the  Tertiary  and  Post-Tertiary  Periods 
were  inhabited  by  the  rhinoceros,  elephant,  camel,  horse, 
beaver,  wild  cat,  wolf,  and  many  quadrupeds,  whose  en- 
tire species  are  now  extinct.  In  these  familiar  haunts, 


*  It  is  not  difficult,  with  the  discoveries  already  made  in  Colorado,  to  call  up 
the  country  as  it  existed  on  the  eastern  side  of  the  mountains  about  the  close  of 
the  Miocene  Period.  A  long  and  wide  lake  covered  the  spot  where  Golden  City 
and  Denver  now  stand,  and  stretched  north  and  south  for  an  immense  distance. 
Its  banks  were  clad  with  forests  of  pines,  palms,  and  gum-bearing  trees.  —Denton. 


THE    POST-TERTIARY   PERIOD.  207 

amid  a  semi-tropical  vegetation,  they  lived  and  died. 
Their  remains,  sinking  in  the  soft  mud,  reveal  to  us 
to-day  the  forms  of  Tertiary  life. 

PO  ST-TERTI  A  RY      PERIOD. 

(Quaternary  Epoch.) 

^3.  Terrace  Epoch. 

POST-TERTIARY  PERIOD.  -<  2.  Champlain  Epoch. 
(  i.  Glacial  Epoch. 

i.     GLACIAL      EPOCH. 

(Drift  or  Bowlder  Period?) 

The  continent  has  been  steadily  growing  through  the 
ages  until  now  it  has  attained  its  full  dimensions.  It 
would  seem  to  be  ready  for  man.  It  abounds  in  coal, 
timber,  water,  game,  and  the  domestic  animals  necessary 
for  man's  use.  We  naturally  expect  his  creation  next, 
and,  almost  unconsciously,  look  about  for  traces  of  his 
presence.  But  God's  plan  is  not  yet  complete.  The  next 
period  seems  one  of  retrogression,  and  a  superficial  view 
would  lead  one  almost  to  despair  of  the  result.  We  must 
not,  however,  be  impatient,  but  wait  the  slow  development 
of  Nature's  laws.  The  earth  having  passed  the  ordeal  by 
fire  and  water,  now  enters  upon  that  by  ice.  The  long 
summer  is  over.  For  ages  a  tropical  climate  has  pre- 
vailed, and  on  the  borders  of  the  Arctic  Ocean  animals 
have  roamed  and  plants  have  flourished  which  now  find 
a  home  only  beneath  the  burning  sun  of  the  Tropics. 
Their  reign  is  past.  A  tedious  Arctic  winter  succeeds. 
During  its  rigors  life  disappears,  and  half  of  the  conti- 
nent reverts  to  its  primeval  desolation.  Let  us  uotico 


THE     AGE      OF     MAMMALS. 

some  of  the  traces  of  this  wonderful  change — this  appar- 
ent check  in  the  world's  progress. 

1)rift.  — This  includes  the  loose  un stratified*  deposits 
of  clay,  sand,  gravel  and  stones  familiar  to  all  inhabit- 
ants of  the  northern  States.  It  does  not  extend  south  of 
latitude  39° f  nor  west  of  the  Rocky  Mountains  (Whii> 
ney  and  Foster).  In  some  places  the  Drift  material  forms 
only  a  slight  covering  over  the  solid  rock,  while  in  others 
it  is  piled  up  in  hills  and  ridges. 

BOWLDERS. — The  stones  are  of  all  sizes,  from  small 
cobble-stones  up  to  great  rock-masses.  In  Whitingham, 
Vt,  is  a  bowlder  whose  length  is  forty  feet,  and  whose 
estimated  weight  is  3,400  tons ;  another  in  Bradford, 
Mass.,  is  30  feet  square.  Plymouth  Rock  is  a  bowlder  of 
syenitic  granite,  ledges  of  which  are  to  be  seen  near 
Boston.  The  pedestal  of  the  statue  of  Peter  the  Great 
was  hewn  from  a  block  of  granite  weighing  1,500  tons, 
which  was  found  in  a  neighboring  marsh.  Bowlders  are 
sometimes  so  nicely  poised  that  they  can  be  rocked  by 
the  hand,  although  an  immense  force  would  be  required 
to  dislodge  them. 

Bowlders  are  more  or  less  rounded,  as  if  water-worn, 
and  their  structure  and  mineral  composition  are  different 
from  those  of  the  rocks  on  which  they  rest.  They  have 
evidently  been  transported  to  the  places  they  occupy. 

*  When  the  deposit  is  arranged  in  layers,  it  is  termed  Modified  Drift.  Mod- 
ified Drift  at  many  places  forms  knolls  of  a  most  picturesque  description.  On 
account  of  their  beauty,  they  are  oftentimes  chosen  for  burial  places.  Mt. 
Hope  at  Rochester,  and  Woodlawn  at  Elmira,  N.  Y.,  Mt.  Auburn  at  Cam- 
bridge, and  the  cemeteries  at  Plymouth,  Newburyport,  and  North  Adams,  Mass., 
are  all  delightfully  located  on  sites  of  this  formation. 

t  39°  is  about  the  latitude  of  Washington,  Cincinnati,  St  Louie,  Kansas  City, 
Pike's  Peak,  and  Sacramento  City. 


THE     POST-TERTIARY    PERIOD. 


209 


The  "parent  ledges "  from  which  they  were  derived  can 
generally  be  found  at  the  north  of  the  locality— some* 

FIG.  lor. 


View  near  Gloucester,  Mass. 

times  at  a  distance  of  a  few  rods  only,  at  others  of 
many  miles.  Long  Island  and  Martha's  Vineyard  are 
covered  with  rocks  derived  from  the  main-land.  The 
southern  part  of  Rhode  Island  is  strewn  with  iron  ore 
from  Iron  Hill  (Cumberland,  R.  I.).  On  Hoosic  Moun* 
tain  is  a  bowlder  of  500  tons  weight,  which  has  been 
carried  from  a  ledge  across  an  intervening  valley  1,300 
feet  deep,  and  at  the  same  time  elevated  1,000  feet  above 
its  source.  Masses  of  native  copper  from  Lake  Superior 
are  scattered  over  Wisconsin,  Michigan,  and  even  Ohio 
and  Indiana.  The  streets  of  Cincinnati  are  paved  with 
stones  quarried  by  the  hand  of  Nature  in  the  region  of 
the  Upper  Lakes  (Winchell).  Azoic  rocks  are  found 
on  the  western  prairies,  from  400  to  600  miles  distant 
from  their  homes,  (Such  bowlders  are  significantly 


%10  THE     AGE     OF    MAMMALS. 

termed  lost  rocks*  A  bushel  of  pebble-stones  gathered 
in  any  northern  State  will  often  represent  nearly  every 
geological  formation  found  for  hundreds  of  miles  north 
of  that  locality. 

GLACIAL  STRIDE. — A  careful  examination  of  many  of 
these  bowlders  shows  us  that  they  are  covered  with  paral- 
lel grooves  (strice).  These  have  obviously  been  caused 
by  the  scraping  of  the  bowlders  on  the  solid  rock,  as  if  the 
Drift  material  had  been  carried  forward  by  an  irresistible 
force,  since  the  "bed  rock"  (the  rock  in  place)  in  the 
regions  covered  by  the  Drift  is  polished  and  grooved  in  a 
similar  manner.  These  striae  consist  of  long,  straight, 
parallel  lines, — furrows  a  foot  broad  and  several  inches 
deep,  or  scratches  fine  as  a  pin  would  make.  The  sur- 
faces of  hard  rocks,  as  quartz,  are  often  polished  smooth 
as  glass,  while  the  markings  can  be  seen  only  with  the 
microscope.  The  general  course  is  that  in  which  the 
bowlders  have  been  carried,  i.  e.,  from  north  to  south,f 

*  In  New  England,  oftentimes  the  surface  for  many  miles  is  covered  with 
these  erratic  blocks  ;  on  the  prairies,  however,  they  are  found  only  occasionally. 
This  may  he  caused  by  the  different  character  of  the  rocks  at  the  east  and  at  the 
west.  While  every  location  shows  the  intrusion  of  foreign  material,  the  great 
mass  is  made  up  by  the  destruction  of  neighboring  rocks.  The  Silurian  and 
Devonian  rocks  of  the  Mississippi  valley  would  naturally  produce  a  soil  far 
different  from  that  of  the  crystalline  and  metamorphic  rocks  of  New  England. 
The  agent  which  transported  the  rocks  might  have  ground  the  softer  class  to  an 
impalpable  powder,  and  left  the  other  of  a  far  coarser  texture. 

t  "In  general,  these  striae  do  not  alter  their  course  for  any  topographical 
feature  of  the  country.  They  cross  valleys  at  every  conceivable  angle,  and  even 
if  the  striae  run  in  a  valley  for  some  distance,  when  the  valley  curves  the  striae 
will  leave  it,  and  ascend  hills  and  mountains  even  thousands  of  feet  high.  But 
these  striae  are  never  found  upon  the  south  sides  of  mountains,  unless  for  a  part 
of  the  way  where  the  slope  is  small.  Mt.  Monadnoc,  of  New  Hampshire,  is  an 
illustration  of  these  statements.  It  is  a  naked  mass  of  mica  schist,  3,250  feet 
high,  rising  like  a  cone  out  of  an  undulating  country.  And  from  top  to  bottom 
it  has  been  scarified  on  its  northern  and  western  sides,  indicated  by  striae  run- 
ning up  the  mountain,  at  first  south-easterly,  and  at  the  top  at  S.  10'  E.  There 
are  deep  furrows  and  other  phenomena  on  the  summit,  and  the  striae  extend  a 
short  distance  up  the  southern  slope  of  the  mountain."—  Hitchcock. 


THE    POST-TERTIARY    PERIOD. 

varying  generally  not  more  than  50°  east  or  west.  There 
are  frequently  two  or  more  sets  of  striae,  differing  a  little 
in  direction.  At  Stony  Point,  Lake  Erie,  the  limestone 

FIG.  102. 


Bowlder  Scratches. 

lies  exposed  above  the  level  of  the  water.  The  bed  is 
planed  down  smooth  as  a  floor,  and  at  one  place  the  par- 
allel grooves  strikingly  resemble  the  deep  ruts  produced 
by  a  loaded  wagon.  On  the  Platte  river  there  is  a  ledge 
of  limestone  so  regularly  planed  that,  without  further 


THE     AGti     OF    MAMMALS. 


working,  it  can  be  used  for  caps  and  sills  in  houses.  At 
Marquette,  on  Lake  Superior,  there  are  surfaces  as 
uniform  as  if  worked  to  a  level  and  afterward  rubbed 
with  sand-paper.  Near  the  sea-shore  at  Portland,  Maine, 
the  striae  run  parallel  for  great  distances  and  then  dis- 
uppear  in  the  water.  Everywhere  in  the  northern  part 
of  the  continent,  up  to  a  height  of  five  or  six  thousand 
feet  above  the  level  of  the  sea,  where  the  bed-rock  is 
laid  bare,  it  is  found  covered  with  these  Drift-tracings. 
We  can  best  understand  the  cause  of  the  Drift  phenom- 
ena by  noticing  similar  cases  now  exhibited  in  Alpine 
regions. 

GLACIAL  PHENOMENA.  —  The  snow  which  falls  on  the 
mountains  of  Switzerland,  above  the  so-called  snow 
line,  does  not  melt,  but  accumulates  to  a  great  thickness. 
By  its  own  weight  it  generally  packs  into  a  solid  mass. 
Thawing  superficially  by  day,  tiny  streams  of  water  per- 
colate through,  and  convert  it  into  the  beautiful  azure- 
tinted  ice,  so  much  admired  by  tourists.  Seas  of  ice 
(mers  cle  glace]  fill  the  spaces  between  the  summits,  while 
from  them,  down  every  valley,  pour  rivers  of  ice,  glaciers, 
from  200  to  5,000  feet  deep.  These  ice-streams,  fed  by 
the  snows  above,  extend  downward  until  they  are  melted 
by  the  summer  sun  in  the  valley  below.  They  sometimes 
plough  irresistibly  into  the  cultivated  fields,  so  that  a 
person  can,  with  one  hand,  touch  the  growing  corn,  and 
with  the  other  the  descending  ice-wall.  The  glacier  ad- 
vances down  the  mountain  at  the  rate  of  from  eight  to 
twelve  inches  per  day.  Frost,  rain,  hail,  and  avalanches 
of  snow  are  continually  detaching  from  the  mountain- 
peaks  masses  of  rock,  which  roll  down  upon  the  glacier. 
If  the  ice  were  stationary  these  would  merely  gather  in  a 


THE    POST-TERTIARY    PERIOD. 

confused  pile,  but  owing  to  the  forward  movement  of  the 
glacier,  they  form  along  the  outer  edge  a  line  of  stones 
which  is  termed  a  Moraine.  When  the  rocks  fall  from 
opposite  mountains  and  on  each  side  of  the  glacier,  they 
make  two  parallel  trains  which  are  called  Lateral  Mo- 
raines (Fig.  103).  At  the  foot  of  the  glacier  the  debris 
gathers  in  ridges,  styled  Termini  Moraines.*  In  thi 
way  enormous  blocks  of  stone  have  been  carried  many 
miles.  They  are  often  found  perched  on  points  of  the 
Alps  far  above  existing  glaciers,  or  dispersed  over  distant 
plains.  Masses  thus  conveyed  on  the  surface  of  the 
glacier  are  little  worn.  Blocks,  pebbles,  etc.,  however, 
which  become  frozen  in  the  ice,  are  forced  along  in  the 
onward  progress  of  the  glacier,  scoring  the  rock  beneath 
with  parallel  lines,  and  smoothing  its  surface  as  emery 
polishes  steel,  while  they  are  themselves  rounded  and 
scratched  in  every  direction,  and  even  ground  into  im- 
palpable powder.  The  glacier  thus  becomes  a  gigantic 
rasp  hundreds  of  feet  thick,  thousands  wide,  and  miles 
in  length,  scouring  the  rocks  between  and  over  which 
it  passes. 


*  "  The  masses  of  snow  which  hang  upon  the  Alps  during  winter,  the  rain 
which  infiltrates  between  their  beds  during  summer,  the  sudden  action  of  tor- 
rents of  water,  and  more  slowly,  but  yet  more  powerfully,  the  chemical  affini- 
ties, degrade,  disintegrate,  and  decompose  the  hardest  rocks.  The  debris  thus 
produced  falls  from  the  summits  into  the  circles  occupied  by  the  glaciers  with  a 
great  crash,  accompanied  by  frightful  noises  and  great  clouds  of  dust.  Even  in 
the  middle  of  summer  I  have  seen  these  avalanches  of  stone  precipitated  from 
the  highest  ridges  of  the  Schreckhorn,  forming  upon  the  immaculate  snow  a 
long  black  train,  consisting  of  enormous  blocks  and  an  immense  number  of 
smaller  fragments.  In  the  spring,  a  rapid  thawing  of  the  winter  snows  often 
causes  accidental  'torrents  of  extreme  violence.  If  the  melting  is  slow,  water 
insinuates  itself  into  the  smallest  fissures  of  the  rocks,  freezes  there,  and  rends 
asunder  the  most  refractory  masses.  The  blocks  detached  from  the  mountains 
are  sometimes  of  gigantic  dimensions  ;  we  have  found  them  sixty  feet  in 
length,  and  those  measuring  thirty  feet  each  way  are  by  no  means  rare  in  the 
Deux  Mondes— Martin. 


AGE     OF    MAMMALS. 

Evidences  of  Former  Glaciers.  —  Moraines, 
erratic  blocks,  polished  surfaces,  striae,  etc.,  become  to 
the  geologist  infallible  signs  of  the  former  existence  of 
glaciers,*  and  enable  him  to  follow  them  in  their  course 
and  fix  their  origin.  One  who  is  familiar  with  tracing 
the  furrows  of  this  mighty  ice-plow  will  recognize  at  once 
where  the  large  bowlders  have  hollowed  out  their  deeper 
gashes,  where  small  pebbles  have  drawn  their  finer  marks, 
where  the  stones  with  angular  edges  have  left  their  sharp 
scratches,  and  where  fine  sand  and  gravel  have  rubbed 
and  smoothed  the  rocky  surface,  and  left  it  polished  as 
if  it  came  from  the  hand  of  the  marble-worker. 

Glaciers  of  Greenland. — Glacial  phenomena  are 
displayed  on  the  grandest  scale  in  Greenland.  On  its 
western  coast  is  a  glacier  1,200  miles  long.  It  presents 
to  the  voyager  a  perpendicular  wall  of  ice  2,000  feet 
high.  A  great  glacial  river,  says  Kane,  seeking  outlets 
at  every  valley,  rolling  icy  cataracts  into  the  Atlantic  and 


*  Some  or  all  the  marks  above  enumerated  are  observed  in  the  Alps  at  great 
heights  above  the  present  glaciers  and  far  below  their  actual  extremities ;  also 
in  the  great  valley  of  Switzerland,  fifty  miles  broad :  and  almost  everywhere  on 
the  Jura,  a  chain  which  lies  to  the  north  of  this  valley.  The  average  height  of 
the  Jura  is  about  one-third  that  of  the  Alps,  and  it  is  now  entirely  destitute  of 
glaciers ;  yet  it  presents  almost  everywhere  similar  moraines,  and  the  same  pol- 
ished and  grooved  surfaces  and  water-worn  cavities.  The  erratics,  moreover, 
which  cover  it  present  a  phenomenon  which  has  astonished  and  perplexed  the 
geologist  for  more  than  half  a  century.  No  conclusion  can  be  more  incontest- 
able than  that  these  angular  blocks  of  granite,  gneiss,  and  other  crystalline  for- 
mations came  from  the  Alps,  and  that  they  have  been  brought  for  a  distance  of 
fifty  miles  and  upward  across  one  of  the  widest  and  deepest  valleys  in  the 
world ;  so  that  they  are  now  lodged  on  the  hills  and  valleys  of  a  chain  composed 
of  limestone  and  other  formations,  altogether  distinct  from'  those  of  the  Alps. 
Their  great  size  and  angularity,  after  a  journey  of  so  many  leagues,  have  justly 
excited  wonder;  for  hundreds  of  them  are  as  large  as  cottasres;  and  one  in  par- 
ticular, composed  of  gneiss,  celebrated  under  the  name  of  Pierre  &  Bot,  rests  on 
the  side  of  a  hill  about  900  feet  above  the  Lake  of  Neufchatel,  and  is  no  less  than 
forty  feet  in  diameter.— Lyett. 


TH£!    POST-TERTIARY    PERIOD. 


the  Greenland  seas,  and  at  last  reaching  the  northern 
limit  of  the  land  which  has  borne  it  up,  pours  a  mighty 
frozen  torrent  into  Arctic  space.  Unlike  the  Alpine 
glaciers,  which  melt  in  the  warm  valleys  below,  this 
empties  into  the  ocean,  and  vast  masses  becoming  de- 
tached, are  floated  away,  to  be  dissolved  in  the  milder 
water  of  southern  seas.  Thousands  of  these  icebergs 
throng  the  northern  ocean,  freighted  with  debris  to  be 
deposited  on  the  sea-bottom  of  lower  latitudes.*  Could 
we  examine  the  track  of  these  ice-rafts,  we  should  doubt- 
less find  striae  cut  in  the  polished  rocks,  and  blocks  de- 
posited in  long  trains  where  the  bergs  had  struck, 
scraped  along  by  their  enormous  momentum  and  at 
last  stranded. 

We  are  now  prepared  to  understand  the  meaning  of 
the  Drift  phenomena. 

Origin  of  the  3)rift.  —  The  Arctic  regions  are 
elevated,  f  The  climate  of  the  whole  continent  feels  the 
change.  The  cold  creeps  down  every  valley.  Each 
northern  blast  brings  a  frost.  The  verdure  of  forest 
and  plain  withers  and  falls.  The  sun  loses  a  part  of 
its  heat.  The  sea  becomes  cold.  Tertiary  life  perishes 


*  Describing  Cape  James  Kent,  Kane  says :  "As  I  looked  over  this  ice-belt, 
losing  itself  in  the  far  distance,  and  covered  with  millions  of  tons  of  rubbish- 
greenstones,  limestones,  chlorite  slates,  rounded  and  irregular,  massive  and 
ground  to  powder— its  importance  as  a  geological  agent  in  the  transportation  of 
Drift  struck  me  with  great  force.  Its  whole  substance  was  covered  with  these 
contributions  from  the  shore ;  and  farther  to  the  south,  upon  the  now  frozen 
waters  of  Marshall  Bay,  I  could  recognize  raft  after  raft  from  last  year's  ice-belt, 
which  had  been  caught  up  by  the  winter,  each  one  laden  with  its  heavy  freight 
of  foreign  material."— Arctic  Expedition. 

t  It  is  proper  to  remark  that,  while  all  geologists  agree  as  to  the  temperature 
of  this  period,  all  do  not  accept  the  theory  given  above  as  to  the  cause  of  the 
cold.  Many  different  opinions  are  advanced.  The  above  is  supported  by  Dana, 
Winchell,  aad  many  prominent  geologists.  (Sea  note  in  QUESTIONS,  p.  272.) 

10 


218  TEE    AGE    Of    MAMMALS. 

in  this  frigid  temperature.  Arctic  vegetation  covers  the 
land  where  tropical  flowers  have  so  lately  bloomed  in 
beauty.  The  musk-ox  and  the  reindeer  roam  the  south 
of  Europe  where,  in  modern  times,  are  to  grow  the  olive 
and  the  vine.*  New  species  of  animals  spring  into  being, 
clothed  with  a  raiment  of  wool  to  protect  them  from  the 
rigors  of  the  climate,  and  furnished  with  teeth  of  a 
peculiar  complexity,  to  enable  them  to  browse  on  the  new 
vegetation.  Rivers  are  stopped  and  turned  to  ice.  Snow 
gathers  in  the  wintry  air,  and  wraps  in  its  mantle  of 
white  all  the  desolation  that  has  been  wrought.  Glaciers, 
born  in  the  icy  north,  invade  the  land.  Sullenly  they 
move  southward,  along  every  great  river  valley,  f  plough- 
ing the  rock,  paring  down  acclivities,  J  filling  up  ancient 


*  In  the  Drift  are  found  the  musk-ox,  the  reindeer,  the  walrus,  the  seal,  and 
many  kinds  of  shells  characteristic  of  the  Arctic  regions.  The  northernmost 
part  of  Norway  and  Sweden  is  at  this  day  the  southern  limit  of  the  reindeer  in 
Europe ;  but  their  fossil  remains  are  found  in  large  quantities  in  the  Drift  ahout 
the  neighborhood  of  Paris,  and  quite  recently  they  have  been  traced  even  to  the 
foot  of  the  Pyrenees.  Side  by  side  with  the  remains  of  the  reindeer  are  found 
those  of  the  European  marmot,  whose  present  home  is  in  the  mountains,  about 
6,000  feet  above  the  level  of  the  sea.— Agassiz's  Geological  Sketches. 

t  The  Connecticut  Valley  seems  to  have  had  an  independent  glacier,  as  the 
striae  are  parallel  with  the  general  course  of  the  river;  the  Mohawk  another;  the 
Hudson  a  third  one ;  and  traces  of  many  smaller  ones  are  being  discovered. 

%  The  current  view  that  all  the  Drift  or  soil  of  the  northern  regions  has  been 
produced  by  glaciers  breaking  up  and  grinding  to  pieces  solid  rocks,  is  opposed 
by  Bnrbank.  In  extensive  observations  at  the  South,  below  the  line  of  the 
Drift,  he  found  the  material  of  rocks  apparently  decomposed  in  places  to  the 
depth  of  25  or  30  feet.  Contrasting  with  this  the  very  small  amount  of  disintegra- 
tion which  has  taken  place  among  similar  rocks  now  exposed  to  the  surface  in 
the  same  regions,  he  concludes  that  the  time  which  has  elapsed  since  the  Drift 
Period  must  be  very  short  compared  to  the  ages  during  which  these  solid  rocks 
were  undergoing  decomposition  by  chemical  and  atmospheric  agencies ;  that  the 
immense  amount  of  material  constituti-ng  the  Drift  of  eastern  New  England  can 
be  accounted  for  only  by  supposing  that  the  rocks  were,  before  the  Glacial  Period, 
decomposed  and  disintegrated  to  a  great  depth ;  and  that  while,  of  course,  the 
glaciers  wore  and  ground  down  the  solid  rocks,  yet  their  chief  action  was  to 
carry  forward  and  commingle  the  materials  already  disintegrated. 


THE     P  OSTrTERTIARY    PERIOD 

river-channels,*  burying  forests  under  masses  of  debris, 
scoring  and  polishing  the  surface,  grinding  up  the  stones 
into  soil,  and  strewing  rocks,  gravel,  and  sand  over  south- 
ern fields.  Beaching  the  coast  of  New  England,  they  fringe 
the  ocean  with  an  ice-wall  for  hundreds  of  miles.  Mighty 
icebergs,  breaking  loose,  float  southward,  .and.  grinding 
their  way  through  river-channel  and  strait,  deposit  their 
rocky  burdens  in  long  trains  over  the  sea-bottom, f  or, 
grounding  on  its  shore,  drop  them  in  promiscuous  piles. 

II.  CHAMPLAIN  AND  TERRACE  EPOCHS. 

^Depression  of  the  Continent  (CHAMPLAIN 
EPOCH). — The  epoch  of  Arctic  elevation  ceases.  The 
northern  regions  descend  toward  their  former  level. 
Again  the  continent  feels  a  change.  A  geologic  spring- 


*  There  is  proof  of  the  existence  of  rivers  in  different  channels  from  the 
present.  At  the  Whirlpool,  on  the  west  bank  of  the  gorge,  three  miles  below 
Niagara  Falls,  there  is  a  deep  ravine  filled  w\th  gravel  and  sand.  This  old  chan- 
nel can  be  traced  to  Lake  Ontario,  four  miles  west  of  the  present  mouth  of  the 
river,  and  must  have  been  the  ancient  bed.  During  the  Glacial  Epoch,  the 
mighty  ice-plow  pared  off  the  ridge,  and  filled  the  ravine  with  Drift  materials, 
so  that  the  river  was  forced  to  seek  a  new  route,  and  since  then  has  worn  away 
the  present  tremendous  gorge  between  Queenstown  and  the  Falls.  In  boring 
for  oil,  and  in  excavating  for  railroads,  such  ancient  river-channels,  now  filled 
with  Drift,  are  frequently  found. 

"  In  excavating  one  of  the  canals  for  supplying  the  mills  of  Lowell,  the  old 
channel  of  the  Merrimack  was  found  under  the  Drift  and  alluvium,  half  a  mile 
from  the  present  bed  of  the  river.11 — L.  8.  Burbank. 

t  "There  is  one  of  these  trains  in  Berkshire  county,  Mass.  The  moun- 
tains from  which  the  angular  blocks  of  hard  talcose  slate  have  been  torn 
off,  lies  in  Canaan,  N.  Y. ;  and  from  thence  they  lie  in  trains,  running  for  a 
few  miles  S.  56°  E.,  and  then  changing  to  S.  34°  E.,  and  extending  yet  further, 
making  in  the  whole  distance  not  less  than  fifteen  or  twenty  miles  ;  at  least  one 
of  them  extends  that  distance,  passing  obliquely  over  mountain  ridges  some 
600  or  800  feet  high.  Its  width  is  not  more  than  thirty  or  forty  rods.  The  blocks 
are  of  all  sizes,  from  two  or  three  feet  in  diameter  to  those  containing  16,000 
cubic  feet,  and  weighing  nearly  1,400  tons,  and  in  some  places  almost  cover  the 
surface  of  the  common  Drift,  and  are  not  mixed  with  \V~HUchcock. 


THE     AGE     OF    MAMMALS. 

time  has  come.    The  fetters  of  winter  fall  off.    The  glacier 
feels  the  touch  of  heat,  and  myriad  streams  leap  gladly 

FIG.  104. 


Stream  issuing  from  a  Glacier. 

forth.  The  snow-fields  disappear.  Torrents  of  water, 
hastening  to  the  ocean,  deluge  the  continent.  They  cover 
the  southern  valleys  with  fine  sediment,  the  debris  of  the 


THE     POST-TERTIARY    PERIOD. 

glacier,  and  strew  pebbles  from  the  Appalachian  to  the 
very  border  of  the  Gulf*  (Wmchell).  A  genial  warmth 
pervades  the  air.  Vegetation  springs  to  life.  The  de- 
pression of  the  land  still  continues.  The  ocean  covers 
a  part  of  Maine.  The  Kiver  St.  Lawrence  and  Lake 
Champlain  become  arms  of  the  sea,  tenanted  by  seals 
and  whales.  The  valleys  are  filled  with  broad,  deep, 
majestic  rivers,  whose  waters,  flowing  to  the  sea,  dig 
deep  channels,  open  new  routes  to  the  ocean,  plough 
through  mountain-ridges,  sort  and  sift  the  Drift  debris, 
arranging  it  in  layers,  and  forming  alluvial  deposits  of  a 
great  thickness.  In  many  parts  of  the  northern  States, 
only  the  loftiest  mountains  emerge  above  the  engulf- 
ing waters.  Billows  roll  where  birds  sang  and  flowers 
bloomed.  The  land  gained  during  all  these  long  ages  of 
geological  history  seems  lost  again.  The  ocean  triumphs, 
and  once  more  the  Gulf  joins  its  waters  with  the  Arctic 
Ocean. 

JFlevation  of  the  Continent  (TERRACE  EPOCH). 
— Slowly  the  continent  rises  from  its  last  baptism.  Be- 
fore reaching  its  former  level  it  stops.  The  rivers  dig 
deeper  channels  in  the  soft  alluvial  deposit  of  the  valleys, 
and  leave  their  former  banks  far  up  on  hill-sides  to  mark 
their  submersion  during  the  Champlain  Epoch.  The 
lakes  retire  to  smaller  limits  and  form  new  beaches  like 
the  old  they  have  deserted.  The  ocean  yields  the  sea- 
coast,  where  it  has  so  recently  dashed  in  eager  conquest, 
and  the  land  it  has  just  reclaimed,  and  sullenly  retreats. 


*  There  are  no  "cobble-stones"  in  the  southern  States.  The  streams  do  not 
eeem  to  have  had  sufficient  force  to  carry  the  coarse  material  of  the  Drift.  Thus 
the  sediment  naturally  becomes  finer  toward  the  south,  and  coarser  north. 


THE     AGE     OF    MA  MM  A  LS. 

There  are  several  pauses  of  this  kind  in  the  upward 
progress  of  the  continent.*  At  each  stage  the  retiring 
waters  toy  with  the  sand  and  gravel,  arrange  them  in 
beds,  spread  the  alluvial  soil  upon  the  muddy  bottom, 
and  put  the  finishing  strokes  to  the  work  of  fitting  the 
continent  for  man's  use. 

^Proofs  of  these  Oscillations.— -Over  the  entire 
continent  we  find  in  the  river  valleys,  overlying  the  true 
Drift,  alluvial  deposits  reaching  far  above  the  present 

FIG.  105. 


Terraces  on  Connecticut  River,  south  of  Hanover,  N.  H.  (Dana). 

*  The  author  repeats  in  this  revision  the  statement  made  in  the  first  edition 
t.iat  the  current  theory  of  these  extreme  oscillations  of  the  continent  seems  to 
him  a  purely  artificial  one.  Places  have  been  too  hastily  accepted  as  sea-beaches. 
The  terraces  can  be  mainly,  perhaps  entirely  accounted  for  by  the  damming  up 
of  the  valleys  by  drift  material  and  the  gradual  wearing,  sometimes  sudden 
bursting  of  these  barriers.  Streams  running  along  the  edges  of  the  valleys  when 
the  riven*  were  at  a  high  level,  may  have  produced  the  pot-holes  and  other  phe- 
nomena. 


THE    POST-TERTIARY    PERIOD. 

river  bods.  Looking  up  or  down  the  banks  of  almost  any 
principal  river,  one  can  trace  horizontal  lines,  marking 
one  or  more  terraces  indicating  the  higher  level  of  the 
stream  in  former  times.*  Many  villages  owe  the  beauty 
of  their  sites  to  these  natural  terraces.  At  a  distance 
from  the  present  shore  of  lakes,  we  find  beaches  of  sand 
and  gravel  similar  to  those  now  existing  on  the  borders 
of  the  lakes,  and,  in  general,  parallel  with  them.  There 
are  several  of  these  on  the  south  shore  of  Lake  Erie ;  one 
extending  for  many  miles  is  locally  known  as  the  "  Ridge 
Road."  At  Mackinac  there  are  three  of  these  stair-like 
ridges,  the  highest  100  feet  above  the  present  wrater-level.t 
Remains  of  whales  and  seals  have  been  found  at  Mon- 
treal, and  the  skeleton  of  a  whale  has  been  dug  up  on  the 
borders  of  Lake  Champlain,  sixty  feet  above  its  present 
level.  Near  Brooklyn  a  sea-beach  exists  100  feet  above 
the  ocean.  Along  the  River  St.  Lawrence,  and  in  the 
Champlain  and  Hudson  valleys,  there  are  deposits  termed 
"  Champlain  Clays,"  containing  marine  shells.  They  are 
found  over  500  feet  above  the  ocean.  It  is  evident  that 


*  I  counted  to-day  forty-one  distinct  ledges  or  shelves  of  terrace  embraced 
between  our  water-line  and  the  syenitic  ridges  through  which  Mary  River  forces 
itself.  These  shelves,  though  sometimes  merged  into  each  other,  presented  dis- 
tinct and  recognizable  embankments  or  escarps  of  elevation.  Their  surfaces 
were  at  a  nearly  uniform  inclination  of  descent  of  5°,  and  their  breadth  either 
12,  24,  36,  or  some  other  multiple  of  twelve  paces.  This  imposing  series  of 
ledges  carried  you  in  forty-one  gigantic  steps  to  an  elevation  of  480  feet ;  and  as 
the  first  rudiments  of  these  ancient  beaches  left  the  granite  which  had  once 
formed  the  barrier  sea-coast,  you  could  trace  the  passing  from  Drift-strewn  rocky 
barricades  to  clearly-defined  and  gracefully  curved  shelves  of  shingle  and 
pebbles.  T  have  studies  of  these  terraced  beaches  at  various  points  on  the 
northern  coast  of  Greenland.  They  are  more  imposing  and  on  a  larger  scale 
than  those  of  Wellington  Channel,  which  are  now  regarded  by  geologists  as  in- 
dicative of  secular  uplift  of  coast. — Kane's  Arctic  Explorations. 

t  When  the  lake  stood  at  this  level,  it  is  probable  that  the  water  poured  in 
floods  down  the  Illinois  River  valley,  swelling  it  to  a  mighty  stream.  Traces  of 
its  former  grandeur  are  abundant  far  above  its  present  banks. 


THE     AGE     OF    MAMMALS. 

the  banks  exhibiting  these  remains  were  ancient  sea- 
beaches,  and  that  the  ocean  level  has  since  sunk  and  the 
land  risen.1* 

Fossils  of  the  Tost - Tertiary  Teriod.  —  This 
is  the  current  era  of  geologic  history.  The  record  no 
longer  lies  deep  in  the  solid  rock.  We  find  it  in  the 


*  The  most  distinct  beaches  occur  below  1,200  feet  above  the  ocean  level,  A 
very  fine  beach,  however,  is  found  on  the  west  side  of  the  Green  Mountains,  in 
West  Hancock,  Vt.,  2,196  feet  high.  Others  are  found  in  Peru,  Mass.,  2,022 
feet ;  at  the  Franconia  Notch  of  the  White  Mountains,  2,665  feet ,  and  at  the 
Notch  of  the  White  Mountains  (Gibb's  Hotel),  2,020  feet.  Upon  comparing  to- 
gether the  heights  of  beaches  in  different  parts  of  New  England,  we  find  a  num- 
ber of  them  having  essentially  the  same  elevation ;  thus  showing  that  they  were 
formed  contemporaneously.  For  example,  there  are  beaches  in  Ashfield  and 
Shutesbury,  Mass. ;  in  Norwich,  Corinth,  Elmore,  Hardwick,  and  Brownington, 
Vt.,  each  1,200  feet  above  the  ocean,  and  the  most  remote  are  nearly  200  miles 
apart.— Hitchcock's  Elementary  Geology, 

Page,  in  •'  Chips  and  Chapters,"  referring  to  the  raised  beaches  and  submarine 
forests  of  Great  Britain,  remarks  substantially  as  follows :  From  120  feet  down 
to  the  present  sea-level  we  have  a  series  of  well-marked  shore-lines— 120,  63,  40, 
25,  and  12  feet— marking  a  succession  of  uprises,  all  clearly  pre-historic,  if  we 
except  the  last,  which  indicates  no  very  high  antiquity.  Every  successive  uplift, 
while  it  increased  the  dimensions  of  the  British  Islands,  also  decreased  the 
general  temperature  of  the  country  in  the  proportion  of  1°  F.  for  every  250  feet 
of  uprise  or  nearly.  These -raised  beaches  are  not  all  alike  well  marked  and 
decided,  owing  partly  to  the  nature  of  the  rocks  into  which  they  have  been  re- 
spectively cut,  and  partly  to  the  length  of  time  at  which  the  sea  stood  at  these 
respective  levels.  The  lowest  or  twelve-feet  beach  is  generally  marked  by  ter- 
races of  recent  shells  and  gravel.  Though  the  latest  of  British-raised  beaches, 
this  uprise  must  have  taken  place  long  antecedent  to  history ;  and  there  is  not, 
so  far  as  we  are  aware,  any  certain  evidence  either  of  upheaval  or  depression 
since  the  time  of  the  Romans,  although  certain  misinterpreted  appearances  have 
led  some  observers  to  an  opposite  conclusion.  Any  remains  found  in  the  caves 
of  the  twelve-feet  beach  are  savage  and  pre-Celtic,  showing  that  the  uprise  had 
taken  place  before  (perhaps  long  before)  the  occupation  of  these  primitive  inhab- 
itants. The  twenty-five-feet  beach  is  perhaps  the  most  striking— stretching  for 
miles  in  unbroken  continuity,  composed  in  many  districts  of  recent  shells  and 
gravel,  frequently  backed  by  old  caverned  cliffs,  and  forming  the  level  site  for 
most  of  our  modern  sea-ports  and  fashionable  watering-places.  The  sixty-three- 
feet  beach  is  also  well  defined  on  many  tracts  of  the  seaboard,  but  its  once  over- 
hanging cliffs  have  been  obliterated  by  the  tear  and  wear  of  the  elements,  its 
shells  and  exuviae  dissolved  and  destroyed,  and  its  gravel  beds  now  covered  by 
soil  and  greensward.  Of  the  higher  beaches  little  is  known  with  precision,  or 
accuracy. 


THE     POST-TERTIARY    PERIOD.  226 

marls    and    sediment   of   filled  -  up   lakes ;    in    beds    of 
sand  and  clay ;  in  the  alluvial  deposits  of  rivers ;  in  the 
growth  of  peat-bogs  and  morasses ;  in  the  deep,  muddy 
accumulations  of  swamps ;  in  the  stalagmites  of  fissures 
and  caverns,   and  in  the  ice  of  Arctic  regions.     The 
plant-remains — willow,   hazel,   fir,   beech,   and    oak— are 
familiar  to  those  who  now  live  in  the  same  latitudes. 
The   fresh-water   shells   are  identical  with  those  which 
throng  the   neighboring  ponds.      The   marine   fossils — 
oysters,   clams,   mussels,    etc. — cannot   be    distinguished 
from  those  which  inhabit  the  surrounding  ocean.     When, 
however,  we  turn  to  the  land  animals,  the  change,  prob- 
ably through  the  instrumentality  of  man,  becomes  more 
apparent.     The   quadrupeds,  as  in   the   Tertiary  Period, 
take  the  precedence,  and  attract  our  attention  by  their 
enormous   bulk.     We   shall   describe   the   following :   the 
mammoth,  mastodon,  megatherium,  glyptodon,  Irish  elk, 
cave-bear,  and  hyena. 

I.  THE  MAMMOTH,  or  fossil  elephant,  was  about  one- 
third  larger  than  any  known  to  modern  times.  A  tooth,  in 
the  Ward  cabinet,  Eochester,  weighs  fourteen  pounds.  This 
animal  wandered  in  great  herds  over  England,  thence  to 
Siberia,  and  across  Behring's  Straits  into  North  America. 
Its  remains  are  very  abundant.*  Over  2,000  molar-teeth 


*  In  1663,  Otto  von  Guericke,  the  illustrious  inventor  of  the  air-pump,  wit- 
nessed the  discovery  of  the  bones  of  an  elephant  buried  in  the  shelly  limestone, 
or  muschelkalk.  Along  with  it  were  found  its  enormous  tusks,  which  should 
have  sufficed  to  establish  its  zoological  origin.  Nevertheless  they  were  taken 
for  horns,  and  the  illustrious  Leibnitz  composed,  out  of  the  remains,  a  strange 
animal,  carrying  a  horn  in  the  middle  of  its  forehead,  and  in  each  jaw  a  dozen 
molar-teeth  a  foot  long.  Having  fabricated  this  fantastic  animal,  Leibnitz 
named  it  also ;  he  called  it  the  fossil  unicorn,.  For  over  thirty  years  the  uni- 
corn of  Leibnitz  was  universally  accepted  throughout  Germany,  and  nothing 
less  than  the  discovery  of  the  entire  skeleton  of  the  mammoth  could  change  the 


THE     AGE      OF     MAMMALS. 


were  found  in  a  few  years  by  the  fishermen  of  the  little 
village  of  Happisburg.     The  islands  in  the  sea  north  of 


FIG.  106. 


The  Mammoth  or  Fossil  Elephant. 


THE    POST-TERTIARY    PERIOD. 

Siberia  are  but  conglomerations  of  sand,  ice,  and  the 
tusks  and  teeth  of  elephants.  During  every  storm,  the 
waves  wash  loose  and  cast  ashore  this  fossil  ivory,  which 
becomes  a  profitable  article  of  commerce.  Single  tusks 
are  found  weighing  over  200  pounds.  In  1844,  16,000 
pounds  are  said  to  have  been  sold  at  St.  Petersburg, 
The  ivory  thus  obtained  has  been  exported  to  China  for 
five  centuries,  and  yet  the  supply  seems  undiminished. 
The  colossal  size  of  these  remains  has  given  rise,  among 
the  Tartars,  to  a  curious  legend.  They  were  believed  to 
belong  to  an  enormous  animal — an  elephantine  mouse — 
which  lived  underground,  like  the  mole,  and  which  in- 
stantly perished  when  exposed  to  the  least  ray  of  sun  or 
moon. 

In  1799,  a  fisherman  discovered  among  the  icebergs  on 
the  banks  of  the  Lena,  an  odd-shaped  block  of  ice.  Two 
years  after,  he  found  the  tusks  and  flank  of  a  mammoth 
protruding  from  it,  and  in  five  years  the  entire  body  be- 
came disentangled,  and  fell  upon  the  sand.  He  removed 
the  tusks  and  sold  them.  Two  years  subsequent,  Mr. 
Adams,  of  the  St.  Petersburg  Academy,  heard  of  the  dis- 
covery, and  visited  the  spot.  The  people  of  the  neigh- 
borhood had  cut  off  pieces  of  the  flesh  for  their  dogs,  and 
wild  beasts  had  mangled  it,  but  the  skeleton  was  nearly 
entire.  The  skin  yet  covered  the  head ;  one  of  the  ears, 
well  preserved,  was  furnished  with  a  tuft  of  hair;  the 
neck  had  a  flowing  mane ;  and  the  body  retained  scat- 


popular  opinion,  and  then  not  without  a  keen  controversy.  Tn  1700,  a  veritable 
cemetery  of  elephants  was  discovered  near  the  banks  of  the  Necker  Eiver,  in 
Wurtemberg.  Not  less  than  sixty  tusks  were  exhumed.  As  a  curious  instance 
of  the  superstition  of  the  times,  the  fact  may  be  mentioned  that  the  court 
physician  possessed  himself  of  the  fragments  which  were  left,  to  aid  him  in  com- 
bating fever  and  colic  1  Chinese  apothecaries  now  use  similar  remedies. 


THE     AGE     OF    MAMMALS. 

tered  tufts  of  reddish  wool  and  black  hair.  Mr.  Adams 
collected  the  bones,  repurchased  the  tusks — which  were 
more  than  nine  feet  long — and  sold  this  unique  specimen 
to  the  Emperor  of  Russia  for  $6,000. 

2.  THE  MASTODON  resembled  the  modern  elephant,  but 
had,  in  general,  a  longer  body  and  more  massive  limbs. 

FIG.  107. 


The  Mastodon. 


When  discovered,  Buffon  called  this  animal  the  Elephant 
of  the  Ohio.  A  single  tooth,  however,  is  sufficient  to  dis- 
tinguish its  remains.  The  grinding  surface  of  a  masto- 
don's tooth  is  covered  with  conical  projections — whence 
the  name  of  the  animal— while  that  of  the  elephant  is 
flat.  Teeth  have  been  dug  up  weighing  seventeen  pounds 
each,  and  tusks  fourteen  feet  in  length.  Six  skeletons 


TSJS    POST-TERTIARY    PERIOD. 

were  found  in  Warren  county,  N.  J.,  by  a  farmer  digging 
in  a  bog.  Within  the  ribs  of  one  of  them,  being  evidently 
the  contents  of  the  stomach,  were  seven  bushels  of  vege- 
table matter,  which,  on  microscopic  examination,  proved 
to  consist  of  cedar  twigs,  which  probably  formed  the 
animal's  last  supper.  Similar  discoveries,  and  also  the 
form  of  the  teeth,  prove  that  its  food  was  roots,  small 
branches,  leaves,  grass,  etc.  The  mastodon  was  once 
comrnon  in  the  United  States,  and  probably  wandered 
in  herds  over  all  the  country  west  of  the  Connecticut 
River. 

3.  THE  MEGATHERIUM  *  (monstrous  beast),  at  first 
sight  seems  the  most  ill-formed  creature  we  have  yet 
considered.  We  shall,  however,  find  its  structure  full  of 
harmony  and  adaptation.  It  was  simply  a  huge  sloth  of 
the  size  of  an  elephant.  Like  the  sloth  it  fed  on  leaves, 
and  possibly  like  the  ant-eater,  it  burrowed  deep  in  the 
earth.  Its  fore-feet  were  each  three  feet  long  and  a  foot 
broad,  and  were  furnished  with  gigantic  claws.  Its  tail 
was  two  feet  in  diameter,  and  must  have  assisted  in 
supporting  its  huge  body,  as  it  tore  down  trees  for  its 
food,  while  it  constituted  also  a  powerful  means  of  de- 
fence. Its  massive  proportions  and  clumsy  form  rendered 
it  extremely  slow  in  its  movements,  but  there  was  no 
need  of  rapid  locomotion  in  an  animal  that  merely  bur- 
rowed for  roots  or  browsed  for  leaves  in  a  tropical  forest ; 
neither  was  there  necessity  for  flight,  when  its  most  dan- 
gerous foe,  the  crocodile,  could  be  destroyed  by  a  single 
blow  from  its  gigantic  tail.  Thus  this  mighty  creature 


*  The  megatherium  is  shown  in  Fig.  Ill,  on  the  right  hand ;  the  glyptodon  in 
front  at  the  center,  the  mylodon  just  back  holding  on  to  a  tree,  and  the  masto- 
don at  the  left  and  in  the  rear. 


THE     AGE      OF     MAMMALS. 

lived  peaceful  and  respected  in  spite  of  its  apparently 
unwieldy  structure.* 

4.  THE  GLYPTODON  (sculptured  tooth)  was  a  mammal 
clad  in  the  shell  of  a  turtle.  This  defensive  armor  mea- 
sured sometimes  eleven  feet  in  length,  and  weighed  1,000 
pounds. 

FIG.  108. 


Glyptodon  clavipes. 

5.  THE  IRISH  ELK  was  a  magnificent  and  imposing 
animal.     Its  antlers  were  often  ten  feet  long,  and  spread, 
from  one  tip  to  the  other,  a  distance  of  three  or  four 
yards. 

6.  THE  CAVE  BEAR  was  the  most  formidable  of  the 
ancient  flesh -eating  animals. 

It   attained   the  size  of  a  large  horse.     Some  of  the 


*  During  the  dry  season  a  hunter  discovered,  on  the  banks  of  the  River 
Salado,  S.  A.,  what  appeared  to  be  the  trunk  of  a  tree.  Throwing  his  lasso  over 
it,  with  the  help  of  a  comrade  he  drew  it  upon  the  bank.  It  proved  to  be  an 
enormous  bone  five  feet  through;  the  pelvis  of  what  has  since  been  happily 
styled  the  megatherium.  To  the  countryman  the  bone  appeared  useless.  It 
did  not  make  half  as  good  a  seat  as  a  bullock's  skull— the  arm-chair  of 
the  pampas.  Finally  this,  with  other  bones,  was  sent  as  a  curiosity  to  the 
owner  of  the  land  on  which  they  were  discovered.  Sir  W.  Parish  found  them 
here,  dug  out  others,  and  forwarded  them  to  England.  From  these  remains  the 
casts  now  in  Boston,  Amherst,  etc.,  were  made.— Denton  in  "  Our  Planet." 


THE     POST-TERTIARY     PERIOD. 


231 


skeletons  are  ten  feet  long  and  six  feet  high.  The  ani- 
mal is  so  named  because  it  dragged  its  prey  into  caves, 
where  the  remains  of  a  large  number  of  antediluvian 
repasts  are  found  buried  in  the  stalactites  which  have 

FIG.  109. 


The  Irish  Elk. 


since  accumulated  on  the  floor.  In  the  celebrated  cave 
at  G-aylenreuth,  portions  of  the  skeletons  of  800  cave- 
bears  have  been  identified. 


AGE     OF    MAMMALS. 

7.  THE  HYENA  was  very  abundant  in  England.  The 
bones  of  seventy-five  have  been  discovered  in  a  single 
cavern.  The  cave  at  Kirkdale,  England,*  is  noted  as  an 

FIG.  no. 


"In  the  summer  of  1821,  some  workmen  employed  in  quarrying  stone  upon 
the  slope  of  a  limestone  hill  at  Kirkrlale,  in  Yorkshire,  came  accidentally  upon 
the  mouth  of  a  cavern.  Overgrown  with  grass  and  hushes,  the  month  of 
this  cave  in  the  hill-side  had  been  effectually  closed  against  all  intruders,  and 


Il 


iff 


THE     POST-TERTIARY    PERIOD.  235 

ancient  haunt  of  these  animals.  "  The  stalagmitic  de- 
posit in  this  cavern,  with  its  projecting  bones/'  says 
Buckland,  "  looks  like  a  pigeon-pie  with  pigeon's  legs 
sticking  through  the  crust." 

In  Fig.  110,  a  cave-bear  is  seen  sitting  at  the  mouth  of 
its  den,  watching  the  bones  of  an  elephant,  while,  above, 
a  hyena  waits  the  proper  moment  to  dispute  possession 
with  its  formidable  rival. 


its  existence  had  never  been  suspected.  The  hole  was  just  large  enough  to  admit 
a  man  on  his  hands  and  knees,  and  led  into  a  low  broad  cavern,  with  branches 
opening  out  from  it — some  of  which  have  not  yet  been  explored.  The  whole 
floor  was  strewn  with  hundreds  of  bones,  like  a  huge  dog-kennel.  The  workmen 
wondered  a  little  at  their  discovery,  but,  remembering  that  there  had  been  a 
murrain  among  the  cattle  in  that  region  some  years  before,  concluded  that  these 
must  be  the  bones  of  cattle  which  then  died  in  great  numbers  ;  and  having  thus 
satisfactorily  settled  the  matter,  threw  out  the  bones  on  the  road  with  the  lime- 
stone. A  gentleman,  living  near,  preserved  them ;  and  in  a  few  months,  Dr. 
Buckland,  the  great  English  geologist,  visited  Kirkdale,  and  examined  its  strange 
contents,  which  proved  indeed  stranger  than  any  one  had  imagined ;  for  many  of 
these  remains  belonged  to  animals  never  before  found  in  England.  The  bones  of 
hyenas,  tigers,  elephants,  rhinoceroses,  and  hippopotamuses  were  mingled  with 
those  of  deer,  bears,  wolves,  foxes,  and  many  smaller  creatures.  The  bones 
were  gnawed,  and  many  were  broken,  evidently  not  by  natural  decay,  but  as  if 
snapped  violently  apart.  After  a  complete  investigation,  Dr.  B.  convinced  him- 
self, and  proved  to  the  satisfaction  of  all  scientific  men,  that  the  cave  had  been  a 
den  of  hyenas  at  a  time  when  these  animals,  as  well  as  tigers,  elephants, 
etc.,  existed  in  England  in  as  great  numbers  as  they  now  do  in  the  wildest  parts 
of  tropical  Asia  or  Africa.  The  narrow  entrance  to  the  cave  still  retains  the 
marks  of  grease  and  hair,  such  as  are  seen  on  the  bars  of  a  cage  in  a  menagerie, 
against  which  the  imprisoned  animals  constantly  rub  themselves,  and  there 
were  similar  marks  on  the  floor  and  walls.  The  hjrenas  were  evidently  the 
lords  of  this  ancient  cavern,  and  the  other  animals  their  unwilling  guests ;  for 
the  remains  of  the  latter  had  been  most  gnawed,  broken,  and  mangled ;  and  the 
head  of  an  enormous  hyena,  with  gigantic  fangs  complete,  testified  to  their  great 
size  and  power.  Some  of  the  animals,  such  as  the  elephants,  rhinoceroses,  etc., 
could  not  have  been  brought  into  the  cave  without  being  first  killed  and  torn 
to  pieces.  But  their  gnawed  and  broken  bones  attest  that  they  were  de- 
voured like  the  rest;  and  probably  the  hyenas  then  had  the  same  propensity 
which  characterizes  those  of  our  own  time — to  tear  in  pieces  the  body  of  any 
dead  animal,  and  carry  it  to  their  den  to  feed  upon  it  apart."  (Agassiz.)— A  de- 
tailed account  of  this  investigation,  etc.,  may  be  found  in  "  Reliquiae  Diluvi- 
anse,"  by  Dr.  Buckland. 


236 


THE     AGE     OF    MAMMALS. 


.  —  /•  Gtaciat  J?poch  on  the  (Pacific 
Coctst. — California  shows  no  traces  of  northern  Drift.* 
The  Rocky  Mountains  probably  constituted  a  sufficient 
barrier  against  the  advancing  glacier  that  overwhelmed 
so  large  a  portion  of  the  continent.  Yet  no  section  ex- 
hibits more  frequent  signs  of  glacial  action.  The  glaciers 
were,  however,  confined  to  the  elevated  regions  of  the 
mountains,  as  the  conspicuous  moraines,  stria?,  etc.,  abun- 
dantly prove.  Swift  torrents  sweeping  down  the  slopes 
of  the  mountain  ranges  denuded  extensive  regions  and 

FIG.  112. 


Canon  of  Grai.d  Rivei. 


deposited  vast  quantities  of  Drift-material.     This  erosive 
action  doubtless  broke  up  the  auriferous  rocks  and  as- 


*  Whitney  in  Proc.  Cal.  Acad.  Nat.  Sci.    Foster  says  the  same  remark  holds 
true  throughout  Oregon. 


THE     POST-TERTIARY    PERIOD. 

sorted  the  materials  of  the  rich  gold-fields  of  California. 
The  great  cations  (kan'-yuns)  of  the  Colorado  and  other 
western  rivers  are  believed  "by  Newberry  to  have  been 
worn  out  during  this  period.  They  are. gorges  cut  in  the 
solid  rock,  sometimes  to  the  depth  of  a  mile.  For  days 
the  adventurer  may  travel  along  the  brink  of  such  a  gulf, 
unable  to  cross  or  to  descend  to  the  water  which  winds 
along  so  far  below,  at  the  bottom  of  the  appalling  chasm. 

2 .  Fhe  £oess  (Lo-ess,  from  the  German  I'dsz,  loam). 
— The  alluvial  deposits  along   the  banks  of  rivers   are 
generally  composed  of  coarse  materials  at  the  lowest  por- 
tions, and  fine  loam   (silt)   in  the  higher.     Where  the 
current  is  strongest,  coarse  gravel  is  borne  along,  and 
where  weakest,  only  sand  or  mud.     A  thin  film  of  this 
fine  sediment  is  spread  during  floods  over  wide  areas  on 
either  bank  of  the  stream.     The  well-known  deposits  of 
the  River  Nile,  to  which  Egypt  owes  its  fertility,  are  of 
this  character.     The  aggregate  during  a  century  is  said 
rarely  to  exceed  five  inches,  though  in  all  it  has  attained 
a  vast  thickness. 

Along  the  valley  of  the  Rhine  similar  deposits  of  loam 
have  taken  place  to  a  depth  of  many  hundred  feet.  The 
color  is  of  a  yellowish  gray,  the  structure  very  homoge- 
neous, and  the  composition  like  that  of  the  Nile.  Shells 
most  perfectly  preserved,  whose  fragility  is  too  great  to 
endure  the  rushing  of  a  stream  of  water,  are  quite  abun- 
dant. 

3.  Bhtff Formation.—  This  Loess  or  "Bluff  For- 
mation "  (Swallow)  extends  to  a  great  distance  along  the 
lower  Missouri,  and  often  lines  its  branching  rivers.    It  is. 


238  THE    AGE     OF    MAMMALS. 

very  conspicuous  at  Sioux  City,  Council  Bluffs,  etc.  On 
the  Mississippi  it  reaches  from  the  junction  of  the  Mis- 
souri to  the  delta,  forming  in  the  State  of  Mississippi  a 
belt  ten  or  fifteen  miles  wide,  and  often  seventy  feet  deep 
(Hilgard).  The  color  is  a  buff,  and  its  composition  a 
siliceous  loam.  The  shells  belong  to  existing  species, 
while  the  remains  of  mammoth,  horse,  lion,  musk-ox, 
etc.,  are  of  extinct  species.  We  thence  conclude  that  the 
physical  changes  which  resulted  in  the  destruction  of  the 
land  animals  did  not  extend  to  the  inhabitants  of  fresh 
water.  Foster  thinks  that  the  formation  is  a  lacustrian 
one,  and  that  when  it  was  deposited,  the  land  was  de- 
pressed a  couple  of  hundred  feet  below  its  present  level. 

4 .  Sand  1)unes*  are  hills  of  sand  heaped  up  along 
the  shore.  They  are  formed  by  sand  drifted  inland  by 
the  wind,  as  snow  is  piled  in  drifts.  The  sand  is  driven 
with  such  force  as  to  smooth  the  surface  even  of  quartz 
rocks,  and  to  wear  holes  in  window-glass.  The  sand- 
dunes  of  Cape  Cod,  Long  Island  shore,  Lake  Michigan, 
etc.,  are  conspicuous  features  of  the  landscape.  Some- 
times long,  narrow  sand-ridges,  or  Osars,  extend  back 
from  the  shore  for  miles. 

«J.  The  Mosaic  Account  states  that  on  the  fifth 
day  the  waters  brought  forth  abundantly  the  moving 


*  On  the  east  side  of  Cape  Cod,  clearly  marked  in  many  places  on  the  beach 
between  Provincetown  and  Truro,  the  former  shore-line,  of  the  west  side  may  be 
distinctly  traced.  The  whole  mass  of  sand  forming  that  part  of  the  cape  has 
been  carried  over  westward  into  the  bay.  This  movement  is  still  going  on,  and 
threatens  to  destroy  the  harbor  of  Provincetown.  Parties  of  men  have  therefore 
been  employed  by  the  United  States  government  to  set  out  beach-grass  along 
the  coast.  This,  by  the  extension  and  interlacing  of  its  fibrous  roots,  tends  to 
hold  the  sand  in  place.— Burbank. 


THE     POST-TERTIARY    PERIOD. 

creature  that  hath  life,  the  fowl  that  flies  above  the  earth, 
and  great  whales.  The  sixth  day  was  characterized  by 
two  works — the  creation  of  mammals,  and  lastly  of  man, 
to  be  the  lord  of  all  created  things. 

Geology  gives  us  the  same  general  outline.  In  the 
Palaeozoic  Age,  the  seas  swarmed  with  life.  In  the  Meso- 
zoic  Age,  birds  appeared,  while  reptiles  (styled,  in  popular 
language,  great  whales  or  sea-monsters,  as  the  word  may 
be  translated)  became  the  dominant  life.  In  the  dawn 
of  the  Cenozoic,  mammals  of  enormous  size  and  in  pro- 
digious numbers  covered  the  earth;  while  at  the  close, 
Man  appeared  to  crown  the  creative  work. 

Scenic  Description.— This  glimpse  of  Tertiary 
times  presents  a  scene  of  sylvan  beauty.  Before  us 
is  a  broad  meadow  carpeted  with  grass  and  blooming 
flowers,  while  behind  are  mountains  clad  in  forests  of 
familiar  trees.  In  the  foreground  is  a  lake  stretching 
away  in  the  distance  far  as  the  eye  can  reach,  its  waves 
sparkling  in  the  noontide  sun.  Snipes  make  their  retreat 
among  the  reeds  which  line  the  low  marshy  shore ;  sea- 
gulls skim  the  water ;  owls  hide  themselves  in  the  trunks 
of  old  cavernous  trees ;  gigantic  buzzards  hover  threaten- 
ingly in  the  air,  poised  for  prey ;  great  turtles  crawl  up 
the  bank;  heavy  crocodiles  drag  their  unwieldy  bodies 
through  the  high  marshy  grass ;  and  a  huge  rhinoceros 
wallows,  grunting,  in  the  mud.  Over  the  plain  gallops 
a  troop  of  wild  horses ;  foxes  scamper  through  the  bushes ; 
and  flocks  of  birds  sing  in  the  branches  of  the  willows 
that  border  a  neighboring  brook.  Everywhere  wander 
great,  unwieldy  quadrupeds.  Here  is  a  solitary  megathe- 
rium— a  gigantic  sloth — standing  on  his  massive  hind- 


240  THE      AGE      OF     MAMMALS. 

legs,  and  propped  up  by  his  huge  tail,  which  makes  a 
secure  tripod  support  See,  he  slowly  reaches  out  his 
muscular  arms,  draws  down  branches  and  young  trees, 
and  lazily  feeds  on  their  tender  foliage.  Yonder  is  a  herd 
of  mammoths  with  long  curved  tusks,  broad  flapping 
leathern  ears,  large  as  a  blacksmith's  apron,  and  legs  like 
fleshy  pillars.  Now  they  feed  along  the  bank,  now  they 
trumpet  shrilly  to  their  companions  in  the  forest,  whose 
responses  sound  like  distant  thunder,  and  now  they  go 
crashing  through  the  woods,  tearing  down  trees  for  sport, 
and  leaving  the  limbs  strewn  over  the  ground,  as  if  a 
hurricane  had  passed.  Fierce  beasts  abound.  A  drove 
of  wild  oxen  of  colossal  strength,  maned  and  shaggy, 
feed  over  the  meadow,  and  troops  of  hyenas  prowl  about, 
waging  relentless  war  on  all  weaker  tribes.  Hark !  the 
yelping  of  dogs!  A  pack  of  hounds  out  on  a  hunt.  The 
herd  of  wild  horses  catch  the  dreaded  sound,  snort  with 
fear,  toss  their  manes,  and  go  flying  off  like  the  wind, 
with  their  gaunt  pursuers  in  full  chase.  Scarcely  have 
they  disappeared  when  a  drove  of  camels  stalk  deliberately 
down  to  the  water's  edge,  and  while  they  drink  (as  only 
camels  can),  a  troop  of  monkeys,  chattering  in  the 
branches  overhead,  with  solemn  grimaces,  mock  the  grav- 
ity of  their  slow,  awkward  movements. 


Geology,    which    is   the    story  of  the    rocks,  finds   its  climax  in 
History,  which  is  the  story  of  Man. 


The  Coming  of  Jlfan .  — We  have  no  means  of  de- 
ciding the  exact  time  when  the  human  race  first  appeared 
on  the  earth.  The  most  scientific  man  is  unable  to  name 
centuries  or  years  with  any  degree  of  accuracy  in  connec- 
tion with  any  geological  event.  In  the  loam  (Loess), 
peat-bog  and  cave-earth  of  the  Post-Tertiary  Period  we 
first  find  rude  stone  implements,  tree  canoes,  and  the 
embers  of  the  fire  which  man  alone  can  kindle  or  sus- 
tain. Side  by  side  with  these  are  the  remains  of  the 
mammoth,*  cave -bear,  rhinoceros,  Irish  elk,  etc.  It 
would  seem  that  about  the  time  of  the  glacial  epoch, 
probably  just  as  the  great  ice-floats  began  to  melt  away, 
man  suddenly  appeared  among  the  mighty  quadrupeds 
which  then  covered  the  earth,  to  contest  the  supremacy. 

The  'Primeval  Man. — The  life  of  the  pre-historic 
man  has  been  classified  according  to  the  character  of  the 


*  In  the  valley  of  the  River  Somme,  near  Abbeville,  flint  implements,  associ- 
ated with  remains  of  the  mammoth,  elephant,  hippopotamus,  rhinoceros,  etc., 
were  found  by  M.  Boucher  de  Perthes.  Near  Amiens,  in  the  same  valley,  another 
deposit  of  gravel  was  discovered,  containing  flint  hatchets,  poniards,  knives, 
etc.,  nearly  400  in  number,  accompanied  also  by  bones  of  the  above  animals. 


THE    ERA     Of1    MIND. 


fossil  remains  in  the  following  manner.    (Edouard  Lartet, 
Vogt,  and  others.) 

1.  Epoch  of  extinct  animals,  mam- 

moth, cave-bear,  etc. 

2.  Epoch  of  migrated  existing  ani- 

mals, or  Reindeer  Epoch. 

3.  Epoch  of  domesticated  animals, 

or  Polished  Stone  Epoch. 

1.  The  Bronze  Epoch. 

2.  The  Iron  Epoch. 


I.  THE  STONE  AGE. 


II.  THE  METAL  AGE 


These  terms  indicate  the  successive  progress  of  the 
ancient  races.  Every  nation  seems  to  have  had  some 
such  stages  in  its  advance.  The  Indians  have  hardly 
passed  out  of  their  stone  age.  The  Sandwich  Islanders, 
when  discovered,  were  in  that  age,  while  the  nations  of 
Asia  emerged  from  it  long  before  the  Christian  era. 
Some  of  these  ages  may  have  been  contemporaneous  in 
different  nations. 


HE 


TONE 


GE. 


J?poc?i  of  Uxlinct  dmma/s.—ThQ  primeval  man 
during   this  epoch  dwelt   in  caves,  dressed  in  skins,  and 
FIG.  113.  made    weapons     chipped 

out  of  the  rough  flint 
(Fig.  113),  by  means  of 
which  he  fought  the  cave- 
bear,  hunted  the  Irish 
A  Danish  Axe-hammer.  elk,  and  speared  the  mam- 

moth.     He  was  rude  and  barbarous,  perhaps  a  cannibal, 


THE    STONE    AGE. 


ana  ceremonies/ 


FIG.  114. 


yet  he  made  fire,  instruments  of  offence  and  defence, 
articles  of  pottery-ware 
for  domestic  use  (Fig. 
114),  sewed  skins  into 
garments,  adorned  his 
person  with  strings  of 
rudely  -  carved  shells, 
wrought  out  images 
emblematic  of  his  po- 
litical or  religious  views, 
and  buried  his  dead  in 
caves  with  religious  rites 


^Reindeer  J?poch . 

— In  this    epoch    man 

advanced  in  knowledge,  learned  to  work  in  bone,  ivory, 


Earthen  Vase  found  in  Cave  of  Furfooz 
(Belgium). 


*  In  1842,  on  the  slope  of  a  hill  near  Aurignac,  an  excavator,  named  Bonne- 
maison,  discovered  a  great  vertical  slab  of  limestone  covering  an  arched  open- 
ing. In  the  cave  thus  closed  up  he  found  the  remains  of  seventeen  human 
skeletons.  These  were  removed  to  the  village  cemetery,  and  thus  lost  to  science 
forever.  In  1860,  M.  Lartet,  having  heard  of  the  event,  visited  the  spot,  which, 
during  a  long  course  of  centuries,  had  entirely  escaped  the  notice  of  the  inhabit- 
ants. The  entrance  to  the  cave  was  concealed  by  masses  of  earth,  which, 
having  been  brought  down  from  the  top  of  the  hill  by  the  action  of  water, 
had  accumulated  in  front,  hiding  a  flat  terrace,  on  which  many  vestiges  of  pre- 
historic times  were  found.  As  no  disturbance  of  the  ground  had  taken  place  in 
this  spot  subsequent  to  the  date  of  the  burial,  this  gradual  accumulation  had 
protected  the  traces  of  these  primeval  men.  The  investigations  of  M.  Lartet 
were  attended  with  the  following  results  : — 

He  found  on  the  floor  of  the  cave  a  bed  of  "made  ground"  two  feet  thick. 
In  this  were  some  human  remains  which  had  escaped  the  first  investigations ; 
also  bones  of  mammals  well  preserved,  and  exhibiting  no  fractures  or  teeth- 
marks,  wrought  flint- knives,  carved  reindeer  horns,  and  eighteen  small  sea- 
shells  pierced  in  the  center,  and  doubtless  intended  to  be  strung  together  in  a 
necklace  or  bracelet.  He  found  also  a  quantity  of  the  bones  of  the  cave-bear, 
the  bison*the  reindeer,  the  horse,  etc.  The  perfect  state  of  preservation  of 
these  bones  shows  that  they  were  neither  broken  to  furnish  food  for  man  nor 
torn  by  carnivorous  animals,  as  is  seen  in  many  cases.  It  must  be  concluded. 


THE     ERA      OF     MIND. 

and  reindeer-antlers  (Fig.  115) ;  to  catch  fish ;  to  make 
saws,  knives,  and  other  tools;  to  form  amulets  and 

charms  of  bone;  to 
ornament  the  in- 
struments of  the 
chase;  and  in  his 
leisure  to  sketch  on 
ivory  the  outlines  of 
the  animals  he  pur- 
sued (Fig.  116). 

"Polished  Stone 
JZpoch .  — The  next 

Bone  pierced  by  an  Arrow  of  Reindeer-horn, 

epoch    witnessed    a 

still  higher  condition.  Skiffs  were  made  in  which  the 
primitive  man  ventured  out  on  the  sea,  and  caught  the 
fish  of  deeper  waters.*  He  made  nets  for  fishing  near  the 

then,  that  the  stone  which  closed  the  entrance  to  the  cavern  was  moved  away  for 
every  interment,  and  carefully  put  back  immediately  afterward.  In  explaining 
the  presence  of  so  many  foreign  objects  in  the  burial-cave,  we  must  admit  as 
probable  that  the  customs  which  now  exist  among  savage  tribes — such  as  plac- 
ing near  to  the  dead  body  the  weapons,  hunting-trophies,  and  ornaments  be- 
longing to  the  deceased — existed  among  the  men  of  the  great  bear  and  mammoth 
epoch.  In  front  of  the  cave  was  also  found  the  site  of  an  ancient  fire-hearth, 
where  evidently  the  funeral  banquet  was  held.  In  this  bed  of  ashes  and  char- 
coal an  immense  quantity  of  the  most  interesting  relics  were  discovered— a 
large  number  of  teeth  and  broken  bones  of  herbivorous  animals ;  a  hundred 
flint-knives  ;  two  chipped  flints,  which  are  believed  to  be  sling  projectiles ; 
several  implements  made  of  reindeer's  horn,  etc.,  etc.  Some  of  the  bones  were 
partly  carbonized,  others  only  scorched,  but  the  greater  number  had  been  un- 
touched by  fire.  All  the  marrow  bones  were  broken  lengthwise,  showing  that 
they  had  been  used  at  a  feast  where  the  marrow  from  animal  bones  furnished  a 
delicious  viand.  Traces  of  the  hyena  were  found  at  this  spot.  From  all  these 
signs  we  infer  that  after  the  death  of  one  of  these  primitive  men,  his  friends 
accompanied  him  to  his  last  resting-place,  after  which  they  assembled  together 
to  partake  of  a  feast  in  front  of  his  tomb  ;  then  every  one  took  his  departure, 
leaving  the  scene  of  the  banquet  free  to  the  hyenas,  which  came  to  devour  the 
remains  of  the  meal. 

*  Along  the  coast  of  Denmark,  in  Cornwall  and  Devonshire,  England,  in 
Scotland,  and  even  in  France,  have  been  discovered  what  have  received  the 


THE     METAL     AGE. 

shore.     He  domesticated  the  dog.     He  attempted  agri- 

Frc.  116. 


Sketch  of  a  Mammoth  graven  on  a  Slab  of  Ivory. 

culture ;  raised  corn,  ground  it,  and  thus  became  less 
dependent  on  the  chances  of  the  chase.  He  interred 
his  dead  in  vaults,  and  erected  monuments  to  mark 
their  last  resting-place.  (See  Fig.  117). 


name  of  "kitchen-middens."  They  are  immense  accumulations  of  shells  from 
3  to  10  feet  in  thickness,  and  from  100  to  200  feet  in  width  ;  their  length  is  some- 
times as  much  as  1,000  feet,  with  a  width  of  250  feet.  At  first  seeming,  one 
would  think  them  banks  of  fossil  shells  which  had  been  submerged,  and  after- 
ward volcanically  brought  to  light.  But  it  has  been  discovered  that  these  shells 
belong  to  four  different  species  which  are  never  found  together,  and  conse- 
quently must  have  been  brought  there  by  man.  Nearly  all  the  shells  are  those 
of  full-grown  animals.  Also  traces  of  fire— remains  of  hearths— were  found  in 
these  heaps,  which,  with  the  other  facts,  lead  to  one  conclusion.  Tribes  once 
existed  there  who  lived  on  the  products  of  hunting  and  fishing,  throwing  out 
round  their  cabins  the  remains  of  their  meals,  especially  the  debris  of  shell-fish. 
Hence  the  name,  which  signifies  "  kitchen  heaps  of  refuse."  Nearly  all  these 
kitchen-middens  are  found  on  the  coast,  along  the  fiords,  where  the  action  of  the 
waves  is  not  much  felt.  Some  have  been  found  inland;  but  this  proves  that 
the  sea  once  occupied  those  localities  from  which  it  has  now  retired.  These 
refuse  deposits  consist  mostly  of  various  shells  of  mollusks — such  as  the  oyster, 
the  cockle,  the  mussel,  and  the  periwinkle.  Fishes'  bones,  in  great  abundance, 
are  also  found.  They  belong  to  the  cod,  herring,  dab,  and  eel.  From  this  we 
may  infer  that  the  primitive  inhabitants  ventured  far  out  to  sea,  as  the  herring 
and  cod  can  be  caught  only  at  some  distance  from  shore.  The  remains  also  of 
the  stag,  the  roe,  the  boar,  and  various  other  mammals  are  discovered,  with 
some  traces  of  birds — mostly  aquatic  species.  All  the  long  bones  are  found  split 
to  extract  the  marrow. 


THE     ERA      OP     MIND. 
FIG.  117. 


Row  of  Menhirs  or  Monuments  set  up  on  Tombs  at  Carnac,  Brittany. 


HE 


ETAL 


GE. 


This  age  indicates  a  great  advance  in  civilization. 
Thenard  asserted  that  we  may  judge  of  the  civilization  of 
any  nation  by  the  degree  of  perfection  it  has  attained  in 
working  iron.  We  may  safely  say  that,  without  a  knowl- 
edge of  the  metals,  man  would  have  remained  a  barharian. 
Iron  ores  do  not  readily  attract  attention,  and  their  re- 
duction is  a  very  difficult  process.  The  method  whereby 
iron  becomes  utilized  in  the  arts,  generally  requires  chem- 
ical knowledge  and  high  progress  in  science.  Gold,  how- 


THE    METAL     AGE. 


ever,  is  found  native,  and  by  its  glitter  attracts  the  eye 
even  of  the  savage.  Copper  occurs  pure,  and  its  ores  are 
rather  widely  diffused,  as  are  also  those  of  tin.  It  is 
strange  that  bronze  (brass),  which  is  an  alloy  of  copper 
and  tin,  should  have  been  the  first  metal  used.  We  can 
hardly  understand  the  cause  of  this,  since  the  metals 
must  have  been  known  before  the  alloy  could  be  manu- 
factured. 

^Bronze  JZpoch  .  —  Tools  of  a  better  character  were 
now  made,  and  life  wore  an  improved  aspect.  Extensive 
villages  were  built  on  piles*  driven  deep  in  the  lake- 


*  The  discovery  of  the  remains  of  lake-dwellings  in  Switzerland,  and  their 
connection  with  the  bronze  epoch  —as  first  asserted  by  Dr.  Keller,  of  Zurich,  and 
since  agreed  to  by  all  archreologists — reveal  to  us  many  very  interesting  facts  in 
regard  to  the  pre-historic  natives  of  that  country.  When,  in  the  dry,  cold  winter 
of  1853-1854,  the  waters  of  the  lakes  in  Switzerland  fell  so  far  below  their  ordi- 
nary level,  the  inhabitants  of  Meilen,  on  the  banks  of  Lake  Zurich,  thus  gaining 
from  the  lake  a  tract  of  ground,  set  to  work  to  raise  it  and  surround  it  with 
banks.  In  carrying  out  this  work  they  found  in  the  mud  at  the  bottom  of 
the  lake  a  number  of  piles,  some  thrown  down  and  some  still  upright,  frag- 
ments of  rough  pottery,  bone  and  stone  instruments,  and  various  other  relics 
similar  to  those  found  in  the  Danish  peat-bogs.  Previous  to  this,  various  instru- 
ments and  strange  utensils  had  been  obtained  from  the  mud  of  some  of  the 
Swiss  lakes,  and  piles  had  often  been  noticed  standing  up  in  the  water,  but  no 
one  had  thought  of  attributing  any  great  antiquity  to  these  objects,  or,  indeed, 
made  much  attempt  to  explain  them.  The  fishermen  had  for  some  time  been 
acquainted  with  the  sites  of  some  of  these  lake  settlements,  in  consequence  of 
having  often  torn  their  nets  on  the  piles  sticking  up  in  the  mud.  Thus, 
guides  were  at  hand  to  aid  in  searching  out  the  mystery  of  these  lake  abodes. 
More  than  200  settlements  are  already  known,  and  every  year  fresh  ones  are 
being  found.  The  builders  of  these  lacustrine  dwellings  seem  to  have  pro- 
ceeded on  two  different  systems  of  construction :  either  they  buried  the  piles 
very  deeply  in  the  bed  of  the  lake,  and  on  them  placed  the  platform  which  was 
to  support  their  huts,  or  they  artificially  raised  the  bed  of  the  lake  by  means  of 
heaps  of  stones,  fixing  in  them  large  stakes  to  make  a  firm  and  compact  body. 
Sometimes  these  are  so  high  as  to  rise  above  the  water,  and  form  artificial 
islands  ;  and  some  of  them  are  still  inhabited. 

We  may  reasonably  suppose  that  need  for  security  prompted  the  ancient 
people  thus  to  construct  their  dwellings  over  the  water.  Encompassed  by  vast 
marshes  and  impenetrable  forests,  no  means  could  so  effectually  secure  them 
from  the  attacks  of  wild  beasts  as  to  surround  themselves  with  water.  In  later 


250 


THE     ERA     OF    MIND. 


FIG.  118. 


bottom,  looms  were  erected,  cloth  was  woven  and  made 
into  garments  (Fig.  118).  The  horse,  ass,  ox,  sheep  and 

goat  were  domestica- 
ted in  great  numbers. 
Hatchets,  reaping- 
hooks,  mills,  pend- 
ants, rings,  hair-pins, 
barbed  fish-hooks, 
and  numerous  arti- 
cles of  ornament  were 
manufactured  (Fig. 
119).  The  clothing 
became  more  grace- 
ful, and  the  hair  was 

Woolen  Shawl  found  in  a  Tomb  in  Denmark.  adorned        with        the 

most  elaborate  taste. 

Wheat,  barley  and  oats  were  cultivated.  The  baker's  art 
was  established.  Glass  was  discovered.  Mats  of  bark  and 
cord  were  made.  Apples,  pears,  berries,  and  other  fruits 
were  stored  for  winter's  use. 


J?poc?i.  —  With  the  discovery  of  iron,  civiliza- 
tion rapidly  advanced.  This  metal  marked  the  latest 
period  of  primeval  development.  The  art  of  metallurgy 

times  it  served  to  protect  them  from  sudden  surprises  by  their  enemies  of 
other  clans.  The  number  of  piles  used  in  these  constructions  is  surprising. 
They  were  often  sixteen  or  twenty  feet  long,  and  in  the  stone-heaps  were  some- 
times ten  or  twelve  inches  in  diameter.  The  mind  is  almost  confused  when  it 
endeavors  to  sum  up  the  amount  of  energy  and  strong  will  which,  without  the 
aid  of  iron  implements,  must  have  been  bestowed  in  constructing  these  settle- 
ments. One  of  the  largest,  that  of  Merges,  in  Lake  Geneva,  is  71,000  square 
yards  in  area.  The  huts  themselves  seem  to  have  been  formed  of  trunks  of 
trees  placed  upright  side  by  side,  and  bound  together  by  interwoven  branches. 
A  coating  of  earth  covered  this  wattling.  Some  of  these  huts  having  been  par- 
tially destroyed  by  fire,  arnon^  the  charred  debris  various  articles  have  been 
perfectly  preserved,  such  as  fishing-nets,  basket-work,  corn,  etc. 


THE     METAL     AGE. 


FIG.  119. 


had  made  great  progress  during  the  bronze  epoch,  but 
now  assumed  new  importance.  Extensive  smelting  works 
were  erected.*  The  potter's 
wheel  was  invented.  Better 
tools  were  made  (Fig.  120). 
Silver  and  lead  were  discov- 
ered. Coined  money  was  in- 
troduced and  commerce  flour- 
ished (Fig.  121),  Agriculture 
was  practiced  on  a  large  scale. 
Fruit  trees  were  cultivated. 
Civilization  was  fairly 


es- 


Bronze  Vase  from  the  Tomb  of  Hallstadt. 


tablished.  At  this  point  the 
written  records  and  oral  traditions  take  up  the  story  of 
the  past,  and  the  naturalist's  labors  cease  as  the  histo- 
rian's begin. 

FIG.  1 20. 


Knife  from  the  Lacustrine  Settlements  of  Switzerland. 


FIG.  121. 


The  ^Development  Theory. — This  primeval  man 
shows  no  sign  of  a  development  from  the 
higher  tribes  of  animals.  No  fossil  yet 
found  is  a  link  between  him  and 
the  monkey.  No  ape  ever  made 
any  improvement  on  the  condition  in 
which  he  was  born.  Man,  on  the  other 
hand,  never  stays  where  he  starts.  He 


*  Four  hundred  iron  furnaces  have  been  discovered  by  M.  Quiquerez  in  th« 
Bernese  Jura. 


THE    ERA      OF    MIND. 

continually  progresses.  The  very  names  given  to  the  vari- 
ous ages  and  epochs  of  his  primeval  history  in  Europe  in- 
dicate this  fact.  He  appears  among  those  huge  quadru- 
peds whose  figures  stalk  like  mighty  shadows  across  the 
scenes  of  the  Post-Tertiary  Period,  and  is  at  once  their 
lord  and  master.  He  uses  the  bow  and  spear.  He  be- 
comes a  builder  and  an  inventor,  makes  tools,  subdues 
the  earth,  hews  down  the  forest,  bridges  the  river,  builds 
houses,  tames  wild  animals  and  converts  their  strength  to 
his  purposes,  while  from  every  element  of  Nature  he 
gathers  material  for  use  and  beauty.  Lastly  and  best  of 
all,  he  buries  his  dead  with  religious  ceremonies,  in  care- 
fully constructed  tombs,  and  deposits  in  their  graves  arms 
and  food  for  their  journey  to  the  spirit-land.  "(Togt.) 
His  thought  reaches  out  into  the  life  beyond,  and  he  be- 
trays at  once  the  longings  of  an  immortal  soul. 

Geology  gives  us  no  means  of  answering  that  oft-asked 
question,  whether  there  was  one  or  were  many  centers  of 
man's  creation.  As  far  as  the  facts  go,  however,  the 
sameness  of  the  remains,  wherever  found,  evinces  a  simi- 
larity of  ideas,  and  thus  tends  to  prove  a  common  origin 
for  the  race.  Those  who,  disregarding  the  unity  of  lan- 
guage, of  mental  constitution,  and  of  the  religious  senti- 
ment of  the  human  race,  desire  to  show  that  the  Mosaic 
account  is  only  a  partial  and  blundering  one,  must  look 
for  arguments  elsewhere  than  in  the  records  of  geology. 

Geological  Theories.  — Many  of  the  geological 
theories  we  have  discussed  may  be  set  aside  by  future 
discoveries,  and  be  proved  to  have  been  vain  assumptions. 
They  will  yet,  however,  have  served  a  purpose.  The 
mind  instinctively  demands  order.  Each  theory  is  a  cord 


THE     METAL     AGE. 

on  which  to  string  facts  that  otherwise  might  be  lost. 
Theories  are  generalizations  of  truth.  They  give  consist- 
ency and  interest  to  a  science  that  otherwise  would  be 
only  a  mass  of  discordant  and  uninviting  detail.  Our 
theories  may  yet  be  thrown  away,  but  our  facts  never, 
and  we  can  but  be  grateful  for  the  former  in  that  they 
have  helped  us  to  retain  the  latter. 


World  Unfinished.  —  Creation  is  continually 
going  on  around  us.  Astronomy  teaches  that  the  stars 
are  changing  —  new  ones  flashing  out  in  the  sky  and 
others  fading  away  into  darkness.  Geology  did  not  cease 
when  history  began.  Since  the  coming  of  man,  vast 
physical  changes  have  taken  place.  The  mastodon  and 
Irish  elk  vanished  with  his  first  appearance.  The  dodo 
of  Mauritius  is  known  only  by  tradition.  The  animals 
of  the  present  —  the  ostrich,  beaver,  etc.  —  are  hastening  to 
extinction.  The  mud  and  sands  of  our  sea-shore  will  be 
the  rocks  of  future  hills,  and  the  rocks  of  our  hills  the 
ocean  sediment  of  another  age.  Rivers  have  deserted 
their  old  channels;  the  ocean  has  encroached  on  the 
land;*  lakes  and  marshes  have  disappeared;  volcanoes 


*  There  is  abundant  evidence  to  show  a  slow  subsidence  of  the  whole  eastern 
coast  of  the  United  States,  which  has  been  going  on  for  several  years  past.  The 
movement  is  one  of  alternate  elevation  and  depression  within  the  limits  of  per- 
haps twenty  feet.  A  map  of  Cape  May,  dated  1694,  shows  Egg  Island  as  contain- 
ing 200  acres ;  it  now  contains  less  than  an  acre  at  ebb  tide,  and  is  entirely 
submerged  at  high  tide.  The  light-house  at  the  Cape  has  been  moved  consider- 
ably inland  on  account  of  the  wear.  The  shore  in  front  of  the  boarding-houses 
at  Cape  Island  must  have  worn  away  nearly  a  mile  since  the  Revolution.  Dur- 
ing the  war  of  that  period,  a  militia  artillery  company  had  its  practicing  ground 
here.  Their  gun  was  placed  near  a  house  which  stood  just  outside  the  present 
shore-line,  and  their  target  was  set  up  at  the  outer  side  of  a  corn-field,  three- 
quarters  of  a  mile  east.  Beyond  this  there  were  sand-beaches  for  nearly  or  quite 
a  quarter  of  a  mile,  and  then  the  sea-shore.  The  whole  of  this  ground  is  now 
gone,  and  one  of  the  boarding-houses  has  been  moved  back  twice.  Sandy  Hook 
has  extended  out  to  the  northeast  a  mile  since  the  Revolution.  The  spot  where 


THE     ERA      OF     MIND. 

have  thrown  out  rivers  of  lava,  and  earthquakes   have 
cracked  the  earth's  crust. 

"  There  rolls  the  deep  where  grew  the  tree ; 
O  earth,  what  changes  hast  thou  seen  ! 
There,  where  the  long  street  roars,  hath  been 
The  stillness  of  the  central  sea." — Tennyson. 

The  Origin  of  Man. — Was  man  created  directly 
by  God's  fiat,  or  by  some  intermediate  process  of  second- 
ary causes  ?  "Alas  for  the  impotence  of  science  and  the 
scope  of  our  finite  intelligence!"  We  bring  the  subtlest 
agencies  to  the  accomplishment  of  our  designs — Heat, 
Light,  Electricity — but  when  we  seek  to  develop  from 
them  even  the  intangible  forces  which  clothe  the  decay- 
ing rock  with  verdure,  or  mantle  the  stagnant  pool  with 
slime,  failure  inevitably  waits  upon  us.  In  vain  do  we 
seek  to  associate  vital  manifestation  with  electrical  action ; 
we  may  resolve  the  vital  organism  into  cells  and  granules 
and  nuclei,  but  the  life  eludes  our  proudest  philosophy. 
If,  under  certain  conditions,  inorganic  matter  assumes 
organic  form,  those  conditions  and  the  laws  which  gov- 


the  first  boarding-house  was  erected  at  Long  Branch,  together  with  the  road 
behind  it,  is  now  all  worn  away.  The  loss  is  sometimes  twelve  feet  in  a  year. 
Where  seventy  years  ago  were  cultivated  fields  is  now  the  ship-channel.  At 
several  points  in  New  Jersey  an  enormous  quantity  of  white  cedar  is  found 
buried  in  the  salt  marshes.  This  indicates  extensive  forests  on  land  now  too 
low  and  wet  for  the  growth  of  trees.  Trunks  are  found  sunk  at  all  depths  down 
to  the  underlying  gravel,  and  so  thick  that  in  many  places  a  number  of  trials 
must  be  made  before  a  sounding-rod  can  be  thrust  down  without  striking 
against  them.  Tree  after  tree  from  one  to  two  thousand  years  of  age  lies  crossed 
above  one  another  in  every  conceivable  direction.  These  cedar  logs  are  mined 
and  split  into  shingles,  and  thus  is  carried  on  a  very  extensive  business.  Sub- 
marine forests  exist  on  the  shore  of  Martha's  Vineyard  and  also  at  Rye  Beach. 
All  along  the  sea-coast,  from  South  Carolina  to  Florida,  similar  phenomena  are 
to  be  found  which  seem  to  indicate  a  subsidence  of  the  land.— See  Cook's  Geology 
Of  New  Jersey,  pp.  343-373. 


CONCLUSION. 

ern  them  are  alike  unknown  to  us.  And  so  we  pause 
on  the  threshold  of  created  life,  and,  standing  reverently 
aside,  lay  humbly  down  our  little  wisdom  as  we  recog- 
nize the  unfathomable  greatness  of  the  ONE  ALL-WISE 
CREATOR. 

"  We  have  but  faith  :  we  cannot  know ; 
For  knowledge  is  of  things  we  see ; 
And  yet  we  trust  it  comes  from  Thee, 
A  beam  in  darkness :  let  it  grow." 


CONCLUSION. 

We  have  traced  in  the  dim  light  of  the  past  the  his- 
tory of  our  earth  and  its  inhabitants.  Everywhere  we 
have  found  a  Divine  Hand  shaping  and  moulding  to 
accomplish  a  Divine  ideal.  "  IN  THE  BEGINNING  GOD." 
We  can  add  nothing  to  the  old  Hebrew  declaration.  W<; 
have  gone  back  to  the  origin  of  man,  and  there  too  we 
have  rested  on  that  sublime  truth,  "  IN  THE  BEGINNING 
GOD."  We  have  winged  our  imagination  backward  to  the 
time  when  our  earth  was  "  without  form  and  void,"  and 
here  again  we  have  felt  the  force  of  that  same  statement — 
"IN  THE  BEGINNING  GOD."  The  study  of  science  ought 
never  to  lead  one  astray  from  this  great  fundamental 
thought.  God  has  assuredly  never  written  anything  in 
Nature  contradictory  of  Himself!  Science  and  religion 
alike  are  His  offspring.  Both  will  ultimately  vindicate 
Him  and  His  attributes.  During  this  transitional  period 
they  may  oftentimes  seem  to  clash,  but  they  will  ulti- 
mately come  into  perfect  accord.  He  who,  even  now, 
from  an  elevated  point  surveys  the  contending  hosts  on 


256 


THE     ERA     OF    MIND. 


this  fiercely-fought  field,  will  see  that  the  scientists  and 
the  religionists  are  fast  setting  out,  if  not  even  now 
moving  upon  converging  lines  of  thought.  By-and-by 
they  will  meet.  Forgetting,  then,  the  rancor  and  bitter- 
ness of  the  past  in  the  joy  of  newly-found  truth,  they 
will  clasp  hands,  and  together  cast  the  crowns  of  their 
triumphs— the  triumphs  of  Science  and  Christianity— at 
the  feet  of  their  common  Author,  and  God  shall  be  pro- 
claimed LOUD  OF  ALL! 


Disintegration  of  granite,  resulting  in  the  form  called  tors  or  cheese  rings. 


FIRST     PART 

[  The  figures  refer  to  the  pages  of  the  book.] 

INTRODUCTION. — State  the  origin  of  the  earth  according  to  the 
nebular  hypothesis.  Why  did  the  earth  assume  a  globular  form  ? 
Describe  the  appearance  of  the  first  crust.  The  first  rain.  Why 
was  the  water  hot  ?  What  was  the  effect  of  the  rain  ?  Describe  the 
conflict  between  fire  and  water. 

19.  Where  do  Astronomy  and  Geology  meet?     Meaning  of  the 
term  "day"  in  the  Scriptures?     Give  the  parallel  between  the  Mo- 
saic and  the  geologic  account. 

20.  Give  some  idea  of  the  appearance  of  the  earth  at  that  time. 
Define  Geology. 

21.  How  thick  is  the  earth's  crust?     How  deep  has  it  been  ex- 
amined?    Condition  of  the  interior?     Name  the  six  reasons  given 
to  prove  that  the  interior  is  a  melted  mass.     At  what  rate  does  the 
temperature  increase  as  we  descend  ?     Illustrate.     Name  some  ar- 
tesian wells  that  furnish  warm  water. 

22.  Name  some  geysers  that  throw  up  hot  water.     Cause  of  this 
difference  in  temperature?      Is  the  earth's    crust   steady?    What 
does  this  oscillation  show?    What  are  volcanoes?     How  many  are 
active?     Give  an  illustration  of  the  amount  of  lava  they  throw  out 
at  an  eruption.     Cause  of  volcanoes? 


258  QUESTIONS. 

23.  How  many  earthquakes  have  been  recorded  in  the  last  half 
of  a  century?  Cause  of  earthquakes?*  State  in  what  respects  the 
earth  is  a  microcosm.  In  what  way  is  the  present  to  the  geologist 
the  key  to  the  past  ? 

24-5.  By  what  course  of  reasoning  does  thg  geologist  infer  that 
certain  kinds  of  rocks  were  formed  by  water?  Are  rocks  now  being 
made  in  this  way?  What  does  the  geologist  call  such  rocks? 
How  does  the  ocean  record  the  history  ofrthe  land? 

26.  Where  does  the  geologist  find  the  history  of  the  past  written  ? 
Has  the  ocean  always  been  where  it  is  now  ?     By  what  course  of 
reasoning  does  the  geologist  conclude  that  certain  rocks  have  been 
thrown  up  in  a  melted  state  from  the  interior  of  the  earth? 

27.  What  name  does  he  apply  to  such  rocks?     Can  he  be  mis- 
taken in  the  principle  ?     Define  fossils.     Give  some  illustrations  of 
the  mistakes  the  ancients  made  concerning  them.    Plater's  blunder. 
What  view  was  generally  held  at  a  later  day  ? 

28.  Describe  the  process  of  fossilization.     Are  any  fossils  now 
making?    When  we  find  a  fossil  bone,  what  conclusion  do  we  draw? 
How  can  a  geologist  restore  the  form  of  an  ancient  animal,  deter- 
mine its  habits,  etc.  ?  f 

*  In  the  text  the  theory  of  earthquakes  is  given  as  that  of  "  billowy  pulsations  " 
in  the  crust  resting  on  the  waves  of  a  lava-ocean.  Dana  holds  that  they  are  pro- 
duced by  the  folding  up  of  the  rocks  in  the  slow  process  of  cooling  and  conse- 
quent contraction.  An  earthquake  wave  consists,  as  in  all  wave-motion,  of  a 
progressive  vibration  as  well  as  a  vertical  oscillation  (Phil.,  p.  128).  The  upward 
vibration  seldom  exceeds  two  feet  in  height.  The  forward  movement  has  a  rate 
of  twenty  to  thirty  miles  per  minute,  depending  on  the  character  of  the  crust 
through  which  it  passes  ;  in  the  "  undisturbed  beds  of  the  Mississippi  valley  the 
rate  being  greater  than  among  the  contorted  strata  of  Europe."  Orton  says  that 
no  familiarity  with  earthquakes  enables  one  to  laugh  during  the  shock,  or  even  at 
the  subterranean  thunders,  which  sound  like  the  clanking  of  chains  in  the  realm 
of  Pluto.  All  animated  nature  is  terror-stricken.  The  horse  trembles  in  his  stall. 
The  cow  moans  a  low,  melancholy  tune.  The  dog  sends  forth  an  unearthly  yell. 
Sparrows  drop  from  the  trees  as  if  dead.  Crocodiles  leave  the  trembling  bed  of 
the  river  and  run  with  loud  cries  into  the  forest.  When  the  earth  rocks  beneath 
our  feet,  we  feel  something  beside  giddiness.  "  A  moment,"  says  Humboldt, 
"  destroys  the  illusion  of  a  whole  life."  We  realize  an  utter  insignificance  in  the 
presence  of  that  mysterious  Power  that  guides  the  forces  of  Nature. 

t  "  Such  is  the  unity  and  persistence  of  plan  which  runs  through  the  different 
classes  of  the  animal  kingdom,  that  a  single  tooth,  whether  of  a  living  or  extinct 
species,  will  often  suffice  to  enable  the  expert  to  disclose  all  the  zoological  rela- 
tionships of  the  animal  to  which  it  belonged,  to  delineate  its  form,  and  size,  and 
habits  of  life  ;  as  the  architect  from  a  single  capital  rescued  from  a  ruined  edifice 


Q  UESTIONS. 

29.  Illustrate.     Why  does  a  geologist  think  a  fossil  shell  was 
once  inhabited?     What  does  the  shell  show?     What  proof  is  there 
that  an  Arctic  climate  once  existed  in  England  and  France?     Is 
this  good  reasoning? 

30.  What  reasons  has  the  geologist  for  thinking  that  certain  re- 
gions were  once  covered  with  glaciers  or  icebergs  ? 

31.  How  does  he  know  that  a  race  of  cave-dwelling  men  once 
lived   in    Europe  ?      That    they   were   contemporaneous   with   the 
hyena?     Describe  the  discoveries  that  could  be  made  in  digging 
through  an  old  lake-bottom. 

32.  Give  the  history  of  the  lake  as  deduced  from  such  data.    Can 
we  judge  of  the  antiquity  of  the  lake?     State  what  has  been  found 
in  draining  old  Scottish  lake-bottoms.     The  history  indicated  by 
these  remains.    Tell  about  the  temple  of  Serapis. 

SECOND     PA  RT. 

LITHOLOGICAL  GEOLOGY. — Define.  Name  the  three  classes  into 
which  it  is  divided.  Define  the  term  "  rock." 

40.  What  common  minerals  compose  the  larger  part  of  the 
earth's  crust?  Properties  of  quartz ?  Its  tests? 

42.  Why  are  quartz  pebbles,  etc.,  so  abundant  ?  Size,  clearness, 
etc.,  of  quartz  crystals?  What  is  rock  crystal?  Why  so  called? 


can  declare  not  only  the  general  style  of  the  entire  architecture,  but  can  repro- 
duce the  size  and  proportions  of  the  temple  whose  spirit  and  method  it  embodies. 
Not  less  sublime  than  the  work  of  the  astronomer,  who  sits  in  his  observatory, 
and,  by  the  use  of  a  few  figures,  determines  the  existence  and  position  in  space 
of  some  far-off,  unknown  orb,  is  that  of  the  palaeontologist — the  astronomer  of 
time-worlds — who,  from  the  tooth  of  a  reptile,  or  the  bony  scale  of  a  fish  found 
thirty  feet  deep  in  the  solid  rock,  declares  the  existence,  ages  ago,  of  an  animal 
form  which  human  eyes  never  beheld — a  form  that  passed  totally  out  of  being 
uncounted  centuries  before  the  first  intelligent  creature  was  placed  upon  our 
planet — and  by  laws  as  unerring  and  uniform  as  those  of  the  mathematics,  pro- 
ceeds to  give  us  the  length  and  breadth  of  the  extinct  form  ;  to  tell  us  whether  it 
lived  upon  dry  land,  in  marshes,  or  in  the  sea ;  whether  a  breather  of  air  or 
water,  and  whether  subsisting  upon  vegetable  or  animal  food.  It  is  this  unity  of 
the  laws  of  animal  life  and  organization  running  through  the  whole  chain  of  ex- 
istence, whether  past  or  present,  whether  extinct  or  recent,  that  constitutes  the 
sublime  philosophy  of  palaeontological  studies,  and  assures  us  that  one  enduring 
and  infinite  Intelligence  has  planned  and  executed  every  part  of  creation."— 
Winchelfs  Sketches  of  Creation,  p.  175. 


UESTIONS. 


Its   uses  ?     Illustrate  the  great  variety  of  forms  which  quartz  as- 
sumes.     Describe  rose  quartz. 

43.  Smoky  quartz.     Milky  quartz.    Granular   quartz.     Its  uses. 
Amethyst.      Why   so    called?      Chalcedony.       Carnelian.       Sard. 
Chrysoprase.     Agate.     Name  the  different  varieties  of  agate.* 

44.  What    is    a    cameo?      Describe    some    celebrated    antique 
cameos.     The  process  for  preparing  agates  for  the  market. 

45.  Describe  jasper.     Cause  of  its  color?     Name  and  describe 
the  different  varieties  of  jasper.     What  is  opal?     Its  appearance? 

46.  For  what    is   hydrophane   noted  ?     How  is   this  explained  ? 
What  gives  the  color  to  quartz  pebbles,  sand,  etc.  ?    Show  that  iron 
is  Nature's  universal  dye  !     Describe  flint.     Its  tests.     Hornstone. 
Buhrstone. 

47.  Cause  of  its  cellular  structure?     Origin  of  quartz?     What 
are  diatoms?     How  do  they  form  rocks  ? 

48.  What  is  tripoli?     Fossil   farina?     Infusorial   earth?     Noted 
localities?     Appearance  of  flint,  etc.,  under  the  microscope  ?   What 
conclusion  is    drawn   from   these   facts?     Describe   alumina.     Its 
tests. 

49.  Sapphire.     Corundum.     Emery.     Composition  of  limestone. 
Tests.     Lime.      Calcite.     Iceland  spar.     Its  test.      Chalk.     Calca- 
reous tufa.     The  Tiber  stone. 

50.  What  are  stalactites?     Stalagmites?     Appearance  of  Oolite? 
What  is  marl?     Its  uses?     Dolomite?     Its  test  ?    Marble? 

51.  Describe   the    Parian   marble.      Name   some   works   of   art 
wrought  from  this  stone.     How  is  the  quality  of  marble  often  in- 
jured?    What  is  verde-antique?     Describe  the  process  of  sawing 
marble.     Wherein  is  this  stone  especially  designed  for  man's  use  ? 

52.  Illustrate  the  abundance  of  limestone.     What  was  the  origin 
of  limestone?     Of  chalk  ?     What  does  the  abundance  of  limestone 
prove?     What  is  gypsum  ?     Its  tests  ?     Plaster?     Its  uses? 

53.  Forms  of  crystallized  gypsum  ?     A  noted  locality?     What  is 
plaster  of  Paris?     WThat  are  silicates?     Name  the  six  prominent 
ones.    Tests  of  feldspar.     Three  varieties  of  feldspar.    Their  tests. 
What  is  clinkstone?     Common  clay? 


*  The  peculiar  form  assumed  by  an  oxide  of  iron  in  the  moss-agate  is  said  by 
microscopists  to  be  due  to  the  presence  of  tiny  fossil  sponges  hi  the  stone. 


QUESTIONS.  261 

54.  Kaolin?      Why   are   bricks   red   and   tobacco-pipes   white? 
Common  name  for  mica?    Its  tests?     Its  uses?     In  what  forms  is 
it  found  ?     Describe  hornblende.     Why  so  called  ?     Asbestos.     Its 
uses. 

55.  Augite.      How   distinguished   from   hornblende?*      Talc.f 
Its  tests.     What  is  French  chalk  ?     Soapstone?     Uses? 

56.  What  is  serpentine  ?     Its  tests  ?    Why  so  called  ?    Its  uses  ? 
What  is  chlorite?     Garnet?     Its   tests?     Ancient   name?     Tour, 
maline? 

57.  Name  the  three  general  classes  of  rocks.     Define  sedimen- 
tary rocks.     Name  the  four  divisions  of  sedimentary  rocks.     What 
is  sandstone  ?     Conglomerate  ?     A  siliceous  sandstone  ?    An  argil- 
laceous one  ? 

58.  Name  the  three  kinds  of  conglomerate.     What  is  a  pudding- 
stone  ?     A  breccia?     A  shale  ?     A  sedimentary  limestone  ?     What 
are  the  characteristics  of  the  landscape  in  a  sandy  region  ? 

59.  Define  igneous  rocks.    By  what  other  name  are  they  known? 
Into  what  two  classes  are  they  divided  ?   Describe  trap-rocks.  Why 
so  called  ?     Their  uses  ?     Name  the  four  varieties  of  trap-rocks. 
What  is  basalt  ?     Chrysolite  ?     Greenstone  ?     Common  name  ? 

60.  Describe  porphyry.     Why  so  called  ?    What  is  a  porphyritic 
rock  ?     An  amygdaloid  ? 

6r.  What  form  does  trap  assume  in  crystallizing?  Causes  of 
this  ?  Noted  trappean  scenery  ? 

*  The  soft,  light-colored  pencils  in  tommon  use  are  made  from  a  soap-stone 
rock  found  at  Castleton,  Vt.  It  is  a  silicate,  technically  known  as  argillite.  This 
is  the  only  deposit  fit  for  pencils  as  yet  discovered  in  the  world.  The  rock  is 
blasted,  and  is  worked  immediately,  as  it  soon  becomes  hard  and  brittle,  and 
hence  useless.  The  stone  is  first  split  into  slabs  about  an  inch  thick,  and  then 
sawn  into  blocks  about  seven  inches  long  and  five  wide.  These  are  carried  to 
the  "  splitting  table,"  where  workmen,  with  a  hammer  and  a  bit  of  steel  like  the 
blade  of  a  knife,  split  them  into  little  plates  about  one-third  of  an  inch  thick. 
The  squares  are  now  of  a  tolerably  uniform  size,  about  an  inch  wide,  one-third 
of  an  inch  thick,  and  seven  inches  long,  but  are  very  rough.  They  are  next 
passed  through  a  planing-machine,  which  smooths  them,  and  a  rounding-ma- 
chine,  which  cuts  off  the  corners,  and  then  are  sawed  to  the  proper  length.  Each 
pencil  is  afterward  sharpened  separately  on  a  grindstone.  The  waste  is  very 
great,  as  not  more  than  one-hundredth  of  the  original  stone  appears  in  the  form 
of  pencils.  This  refuse  is  ground  three  grades  finer  than  superfine  flour,  and  used 
to  mix  with  paper  pulp  to  give  it  body,  as  it  is  termed,  and  a  satin  finish. 

t  Talc  is  found  as  a  compact  rock  in  North  Carolina.  It  is  largely  used  as  a 
black-board  crayon. 


Q  UE  S  T I  0  N 8. 

62.  Characteristic  features  of  the  landscape  in  a  trappean  region  ? 
Proof  of  the  igneous  origin  of  basalt  ? 

64.  Curious  relation  between  the  civil  and  geologic  history  of 
trappean  countries  ?     Name  the  three  varieties  of  volcanic  rocks. 
Describe  trachyte  ?     Noted  peak  of  trachyte  ?*     What  is  lava  ? 

65.  Scoria?     Its  uses?    Pumice?     Its  uses?    What  are  the  char- 
acteristic features  of  the  landscape  in  a  volcanic  region  ?     Define 
metamorphic  rocks. 

66.  What  effect  would  melted  lava  have  on  sedimentary  rocks  ? 
Illustrate.     Cause  of  fossils  in  certain  kinds  of  marble  ?     Imperfec- 
tions in  marble  ?     Composition  of  granite?     How  may  its  constitu- 
ents be  distinguished  ? 

67.  What  is  graphic  granite  ?     Is  the  structure  of  granite  uni- 
form ?     Its  value  for  various  uses  ?     Its   location   in  the  earth's 
crust  ?     Process  of  quarrying  granite  ? 

68-9.  Estimate  of  granite  by  the  ancients  ?  Is  granite  a  primi- 
tive rock  ?  Has  the  original  crust  of  the  earth  been  preserved  un- 
changed ?  State  what  changes  it  has  probably  undergone.  Could 
granite  crystallize  directly  out  from  lava  ?  State  the  theory  of  the 
formation  of  granite.  If  granite  be  not  an  igneous  rock,  how  do 
you  explain  the  fact  that  it  has  been  thrown  up  in  a  melted  state  ? 
What  are  the  various  aspects  which  granite  assumes  in  a  land- 
scape ? 

71.  What  is  the  general  appearance  of  a  granitic  region  ?     What 
effect  has  the  pnrity  and  sublimity  of  nature  upon  the  inhabitants  ? 
Difference  between  granite  and  gneiss  ? 

72.  Origin  of  gneiss  ?     Its  use  ?    Appearance  of  gneiss  hills  ? 

73.  What  is  mica  schist?     Character  of  a  mica  schist  landscape? 
What  noted  scenery  is  of  this  description  ?    What  is  syenite  ?    Why 
so  called  ?  Was  this  name  correctly  applied  ?    Is  "  Quincy  granite  " 
a  true  granite  ? 


*  Chimborazo  is  a  trachytic  dome,  which  is  a  characteristic  feature  of  the  moun- 
tain scenery  among  the  Andes,  as  sharp  granitic  pinnacles  are  of  the  Alps.  (See 
page  69.)  It  is  a  majestic  pile  of  snow,  white  as  if  cut  out  of  spotless  marble. 
Yet  it  once  gleamed  with  volcanic  fires.  Its  ancient  name,  Chimpurazu,  meant 
mountain  of  snow.  It  is  a  little  singular  to  notice  how  many  lofty  peaks  in  the 
world  are  thus  named— Himalaya,  Mont  Blanc,  Hoemus,  Sierra  Nevada,  Ben 
Nevis,  Snowdon,  Lebanon,  White  Mountains,  Chimborazo,  and  Illimani.— Or- 
ion's "A  ndts  and  the  A  mazon." 


Q  UE  S  TI  0  NS. 

74.  What  is  quartzite  ?     Repeat  the  effects  of  metamorphic  action 
on  limestone.     Cause  of  colored  veins  in  marble  ?     How  are  rocks 
classified  according  to  their  structure  ? 

75.  Which  class  is  the  more  abundant  on  the   exterior  of  the 
earth's  crust  ?     On  the  interior  ?     Which  is  of  the  greater  value  in 
geologic  study  ?     Does  the  crust  remain  of  the  same  thickness  ? 
How  are  igneous  rocks  worked  over  into  stratified  rocks  ?     How 
are  stratified  rocks  generally  deposited  ? 

76.  Show  how  igneous  action  has  disturbed  this  uniform  arrange- 
ment.    Value  of  this  disturbance  in  geologic  study  ?     Define  out- 
cropping. 

77.  Define  stratum,  formation,  group,  and  lamina.     Name  and 
define  the  various  terms  used  to  indicate  the  position  of  strata. 

78.  When   are  strata  conformable?     What  is  diverse  stratifica- 
tion ?     Distinguish  between  lamination  and   stratification.      State 
the  circumstances  under  which  different  kinds  of  lamination  are 
produced. 

79.  Define  a  fault.     A  jointed  structure.     Illustrate. 

80.  Value  to  the  quarrymen  ?     Cause  of  these  seams  ?    What  are 
folds?     How  produced  ? 

81.  What  is  a  decapitated  fold  ?     Effect  in  apparently  displacing 
strata  ?     Illustrate. 

82.  What  is  a  concretion  ?     The  nucleus  ?    A  septarium  ? 

83.  A  claystone  ?     A  geode  ?     A  beetle-stone  ? 

84.  A  slate  structure  ?     How  produced  ?     How  do  the  unstrati- 
fied  rocks  occur? 

85.  What  is  a  vein  ?     A  dike  ?     Meaning  of  the  term  ? 

86.  State  Hugh  Miller's  beautiful  comparison. 

87.  How  can  the  relative  age  of  veins  or  dikes  be  estimated? 
What  proof  is  there  that  some  veins  have  been  filled  from  below 
with  melted  matter  ? 

88.  Describe  the  various  ways  in  which  Nature  mends  her  rock- 
rents. 

go.  How  have  metallic  veins  been  formed  ?    What  is  a  lode? 


Q  UE  S  TI  0  N  S. 


THIRD       PART. 

HISTORICAL  GEOLOGY. — Define  historical  geology.  Name  some 
of  the  difficulties  the  geologist  finds  in  reading  this  history.  Value 
of  fossils?  Why  does  the  identification  of  a  fossil  identify  a  forma- 
tion ?  Are  the  geologic  ages  clearly  separated  ?  What  terms  are 
used  to  designate  the  lesser  divisions  ? 

96-98.  Name  and  define  the  five  different  Times  of  geologic  his- 
tory. On  what  are  these  divisions  based  ?  Length  of  geologic 
history  ? 

THE  Eozoic  TIME. — Name  the  Eozoic  periods.  Location  of  the 
Eozoic  rocks.  Where  is  the  oldest  land  in  America?*  Was  there 
ever  a  true  Azoic  time?  Is  it  definitely  fixed? 

101.  Name  the  kinds  of  rocks.     How  formed?    What   ores  do 
they  contain  ?     What  is  the  Eozoon  Canadense.     What  are  rhizo- 
pods? 

102.  Is  the  Eozoon  universally  accepted  as  a  fossil  ?     What  effect 
would  its  admission  have?-    State  the  probability  that  life  existed 
at  that  early  day,  and  that  vegetable  life  had  the  precedence.     How 
is  bog-iron  ore  formed  ? 

103.  How  are  the  relative  ages  of  mountains  indicated  ?     What 
are  the  oldest  mountains  in  America?     Describe  the  effect  of  the 
metamorphic  action  on  the  Eozoic  rocks.     Cause  and  effect  of  the 
upheavals. 

104-5.  Show  how  the  frame-work  of  the  continent  was  developed 
in  the  Eozoic  Time.  The  parallel  which  exists  between  the  Mosaic 
and  geologic  accounts. 

THE  PALEOZOIC  TIME. — Name  the  ages  of  the  Paleozoic  Time. 
The  periods.  What  is  the  Cambrian  system  ? 

*  The  oldest  land  in  South  America  is  in  Guiana.  Its  granite  peak  rose  above 
the  ocean  an  island  where  now  expands  a  continent.  Its  Eozoic  rocks,  togethei 
with  those  of  Brazil,  which  afterward  appeared  as  a  cluster  of  islands,  were  for 
ages  the  only  dry  land  south  of  the  Canada  Hills  While  the  Creator  was  build- 
ing up  a  continent  at  the  north,  the  south  seems  to  have  been  left  for  a  later  age 
to  develop.  Carboniferous  vegetation  mantled  the  coal  regions  with  a  gorgeous 
flora,  monstrous  saurians  paddled  the  waters  of  the  upper  Atlantic  coast,  and 
huge  dinotheria  wallowed  in  the  mire  where  now  stand  the  palaces  of  Paris, 
London,  and  Vienna,  but  as  yet  only  the  broad  table-land  of  Guiana  and  Brazil 
appeared  above  the  waste  of  the  Paleozoic  Sea.— See  Ortvrfs  " Andes  and  the 
A  mazon" 


QUESTIONS. 

THE  SILURIAN  AGE. — Why  is  the  age  so  called?  Name  the 
periods  of  the  Silurian  Age.  Why  is  the  New  York  survey  taken 
as  the  basis  of  the  Silurian  and  Devonian  Ages. 

108.  State  the  method  by  which  the  continent  grew.     The  general 
characteristics  of  the  Silurian  Age. 

109.  Location  of  the  Potsdam  rocks?     Kinds  of  rocks?    What 
are  mollusks  ?     What  is  the  Acadian  Epoch  ? 

no-iii.  What  does  the  calciferous  sandstone  of  New  York  be- 
come at  the  west  ?  What  is  it  there  called  ?  What  is  the  Canadian 
Epoch?  Describe  the  lingula.  The  trilobite.  Peculiarity  of  its 
eyes.  Name  the  parts  of  the  trilobite. 

112-114.  Describe  the  atmosphere  of  the  Potsdam  Period.*  The 
early  Silurian  beach.  What  subkingdoms  of  animals  were  repre- 
sented ?  Was  there  any  vegetation?  Any  distinction  of  zones  ? 
Reasons  for  this  uniformity  ?  Show  how  changes  in  the  sea  pro- 
duced corresponding  changes  in  the  life  and  the  rock.  What 
geologic  events  occurred  in  the  Lake  Superior  region  ?  What  are 
the  Sculptured  and  Pillared  Rocks  of  Lake  Superior?  What  val- 
uable ores  are  found  near  Lake  Superior  ? 

115.  Draw  the  parallel  between   the   Mosaic  and   geologic   ac- 


*  Nature  does  nothing  by  halves.  She  does  not  stop  at  fractions  of  enterprises. 
She  never  forsakes  a  part  until  it  becomes  a  whole.  Her  works  are  often  a  pro- 
cess ;  often  is  the  process  long,  but  provision  is  always  made  for  finishing  up  in 
a  congruous  manner  whatever  she  has  undertaken.  Many  human  works  are 
finally  forsaken  at  various  stages  of  incompleteness — machines,  edifices,  books. 
Nature  is  no  Michael  Angelo,  leaving  piles  of  unfinished  productions.  All  her 
parts  bid  us  look  for  wholes.  Did  you  ever  find  a  fraction  whose  integer  is  not 
come  or  coming  ?  When  you  see  the  crescent  moon,  be  sure  that  the  rest  of  the 
sphere  is  by  its  side,  though  for  the  present  unillumined.  Look  more  closely  ; 
perhaps  you  may  discern  the  old  moon  in  the  new  moon's  arms.  Look  more 
closely ;  perhaps  you  may  discover  over  against  yonder  organic  need  in  Nature 
a  full  supply  for  that  need  which  Nature  has  provided.  But  whether  you  dis- 
cover it  or  not,  make  sure  that  the  supply  exists.  Nature  does  not  waste  herself. 
She  has  no  fondness  for  throwing  herself  away  either  wholly  or  in  parts.  If  you 
find  one  of  her  reservoirs,  make  sure  that  there  is  something  to  put  in  it,  and  as 
much  as  it  will  hold.  If  you  find  one  of  her  tools,  be  certain  that  it  has  some- 
thing to  do,  and  as  much  as  it  can  do  well.  A  good  and  careful  provider  is  she, 
and  never  to  be  reckoned  as  an  infidel  who  does  not  care  for  his  own  !  Cuvier 
finds  a  bone,  and  he  at  once  reconstructs  the  whole  animal  to  which  it  belongs. 
How?  On  the  observed  fact  that  whatever  is  needed  to  complement  a  full 
mechanism  in  Nature  exists  or  has  existed— that  wherever  shines  a  Castor  of  a 
demand,  over  against  it  shines  also  the  twin  Pollux  of  a  supply.— 
pp.  233-5. 


Q  UE  STI  0  NS. 

counts.     Location  of  Trenton  rocks?     Principal  kinds  of  rocks? 
Name  the  epochs  in  New  York.     What  is  St.   Peter's  sandstone? 

116.  The  Galena  limestone?     Peculiarity  of  its  scenery? 

117.  Characteristic  fossils  of  the  Chazy,  Bird's  Eye  and   Black 
River  limestones.     What  are  Gasteropods  ? 

118-120.  Describe  the  orthoceratite.  What  is  the  siphuncle  ? 
What  are  Brachiopods?  Cephalopods  ? 

120-121.  Location  of  Hudson  rocks  ?  Name  the  epochs  in  New 
York.  By  what  name  is  the  formation  known  at  the  west  ?  Kinds 
of  rock  ?  Does  it  contain  any  coal  ?  Describe  the  graptolite. 

122.  Were  species  constant?     Did  animals  die  as  now?     What 
subkingdoms  of  animals  existed?     Any  terrestrial  plants ?    What 
mountains  were  elevated  at  the  close  of  the  period  ?     How  is  this 
known  ? 

123.  What  was  the  Geography  of  Hudson  Period  ?     Location  of 
Niagara   rocks  ?      Why   so   called  ?      Name    the   epochs  in    New 
York. 

124.  What  is  Niagara  limestone  called  in  Chicago?     Minerals  at 
Lockport  ?     Appearance  at  the  west  ?     What  abundant  and  inter- 
esting fossils  ?     Describe  the  fucoids. 

125.  The    crinoids.      What    common    name    has   the   crinoid  ? 
What  is  crinoidal  (encrinital)  limestone  ?     Appearance   when  pol- 
ished ? 

127.  Location  of  Salina  rocks?     Kinds  of  rocks? 

128.  Why  is  it  so  destitute  of  fossils  ?     Explain  the  Salt  Springs. 
Location  of  the  Lower  Helderberg  rocks  ?     Kind  of  rock  ?     Name 
of  the  lower  beds  ?     What  is  said  of  the  abundance  of  fossils  ? 

129.  Describe   the   eurypterus.     The  tentaculites.     What  brach- 
iopod  is  common  ?     Geography  of  this  period. 

130.  Location  of  the  Oriskany  rocks.     What  is  the  character  of 
these  rocks  ?     What  fossil  is  common  ? 

131-2.  What  is  said  of  this  old  Appalachian  sea-beach?  Of  the 
climate  ?  What  animals  took  the  lead  ?  What  classes  were  yet 
wanting  to  complete  the  scheme  of  life  ?  Illustrate  the  uniformity 
of  Nature  in  all  ages.  The  changes  which  took  place  in  the  life  at 
various  times. 

THE  DEVONIAN  AGE. — Why  so  called  ?  What  name  has  it  in 
England?  Is  it  a  red  sandstone  in  America?  Name  its  periods. 
Describe  the  general  characteristics  of  the  age.  What  is  the  promi- 
nent feature  ? 


QUESTIONS.  267 

136.  What  is  a  ganoid  ?    Name  and  describe  the  five  principal 
kinds  of  fish — the  coccosteus,  the  pterichthys,  the  cephalaspis,  the 
holoptychius,  and  the  osteolepis. 

137.  Illustrate  their  singular  union  of  reptilian  and  fishy  traits. 
What  is  a  comprehensive  type?    A  prophetic  and  a  retrospective 
one? 

138-9.  Location  of  the  Upper  Helderberg  rocks?  What  other 
name  is  applied  to  them?  Why?  Name  the  epochs.  Which  stone 
is  most  valuable  for  building  purposes?  What  is  "chert"? 
Characteristic  fossils?  Location  of  the  Hamilton  rocks? 

140.  Name  the  epochs  and  describe  the  different  rocks.     Physi- 
cal features  of  districts  underlaid  by  Hamilton  rocks.     What  is  the 
Cliff  limestone  ?    The  Tully  limestone  ? 

141.  By  what  name  is  the  Genesee  slate  known  at  the   west? 
Describe  the  goniatite.    The  cup  coral.     Conchifers.     Difference 
between  them  and  Brachiopods. 

143.  For  what  is  the  phacops  bufo  distinguished  ?    When  did 
terrestrial    plants   first    appear?     Location    of  Chemung    rocks? 
Name  the  epochs  in  New  York.     Under  what  circumstances  were 
the  Chemung  rocks  deposited? 

144.  What    are    its    prominent  fossils?     Origin   of    the   name? 
Locate  the  Catskill  rocks.      What  are  their  characteristics?     The 
fossils  ?     Name  a  common  one  ? 

THE  CARBONIFEROUS  AGE. — Why  so  called  ?  Name  the  periods. 
Describe  the  general  characteristics  of  the  age.  Its  geography. 
The  conditions  favorable  to  the  growth  of  vegetation.  The  forma- 
tion of  coal.  The  frequent  oscillations  of  the  land. 

152.  Location  of  the  Subcarboniferous  rocks?  Kinds  of  rock? 
Curious  appearance  which  they  sometimes  present?  Prominent 
fossils?  Describe  the  "sink  holes"  found  in  this  formation.  The 
caves.  Name  the  subdivisions  of  the  Subcarboniferous  Period  in 
Illinois.  What  group  furnishes  beautiful  geodes?  What  are  the 
so-called  "Rock  Cities?  "  Where  are  they  found  ?  How  are  they 
formed  ? 

154.  Peculiarity  of  the  fish  found  in  the  Mammoth  Cave  ?    What 
animals  appeared,  as  it  were,  before  their  time?     Location  of  Car- 
boniferous rocks?     Name  the  six  great  coal-fields  of  the  United 
States.     What  are  the  False  Coal  Measures? 

155.  Kinds   of  rock?     State   some    facts   with    regard   to    coal 


Q  UE  S  TIO  X S. 

seams.     The  effect  of  pyrites.     What  are  the  characteristic  fos- 
sils ? 

156.  Describe   the  Carboniferous  vegetation.     The  ferns.     The 
calamites. 

157.  The   sigillarise.     The  lepidodendra.     The  stigmariae.     The 
conifers.     Reptilian  remains.     Insects.     Fishes. 

162.  Location  of  Permian  Period.     Why  so  called  ?     Kinds  of 
rock  ?    Curious  kind  of  limestone  found  near  Manhattan,  Kansas  ? 

163.  Describe  the  character  of  the  Permian  fossils.     The  Appa- 
lachian revolution. 

164-5.  Illustration  of  the  subsequent  denudation  seen  at  Cham- 
bersburg,  Penn.  The  metamorphic  action.  Beneficent  effects  of 
this  upheaval  and  metamorphism.  The  progress  of  life. 

THE  MESOZOIC  TIME. — Name  the  periods  of  the  Mesozoic  Time. 
The  general  characteristics  of  the  Age  of  Reptiles. 

167.  Grand   characteristic  ?      The  geography  ?      Origin   of  the 
terms  Triassic  and  Jurassic  ? 

168.  What  name  is  sometimes  given  to   the  Triassic  rocks  in 
Europe?     What  are  the  European  divisions  of  the  Jurassic  rocks? 

169.  Location  of  the  Triassic  and  Jurassic  rocks  in  the  United 
States  ?     Describe  the  formation  of  the  rocks.     Kinds  of  rock.     Is 
coal  found  ? 

170.-  What  change  took  place  in  the  character  of  the  vegetation  ? 
Describe  the  cycad.  Show  that  it  is  a  comprehensive  type.  What 
classes  now  made  their  appearance?  Had  birds  or  mammals  been 
known  before?  Describe  the  various  kinds  of  fossils — insects, 
fishes,  oysters,  crinoids,  etc. 

171.  In  what  families  did  the  class  of  cephalopods  culminate? 
Describe  the  ammonite. 

•172.  How  did  the  ammonite  sink  ?     Describe  the  belemnite. 

173.  Common  names?    What  is  said  of   the  cuttle-fish?    The 
ichthyosaur  ? 

174.  Coprolites?    Beetle-stones? 

177.  Tell  the  story  of  Mary  Anning. 

178.  Describe  the  plesiosaur.     The  pterodactyle.     How  were  the 
fins  of  the  Devonian  fishes  a  prophecy  of  man? 


Q  UE  ST 1  0  NS. 

1 8 1.  Describe  the  dinosaurs.     What  are  the  names  of  the  princi- 
pal of  these  land  reptiles? 

182.  Describe  the  megalosaur.     The  iguanodon.     The  restora- 
tion of  the  latter  animal.     What  striking  illustration  of  the  mutual 
adaptation  of  the  various  parts  of  the  animal  occurred  in  the  restora- 
tion of  the  megalosaur?*   What  naturalist  discovered  this  principle 
in  comparative  anatomy  (p.  203)  ? 

183.  Describe  the  labyrinthodon.    The  ramphorhyncus. 

184-5.  The  "bird-tracks"  of  the  Connecticut  valley.  What  is 
said  of  the  animal  by  which  they  were  made  ?  What  was  the  cli- 
mate at  that  time  ? 

1 86.  Describe  the  Triassic  salt-beds  of  Europe.  The  Triassic 
gold-bearing  rocks  of  California.  What  was  the  origin  of  the  gold 
placers? 


*  The  following  is  an  extract  from  a  letter  on  this  subject  received  from  Dr. 
Hawkins  too  late  for  insertion  in  its  proper  place,  but  which  is  too  valuable  to  be 
omitted : 

"  In  the  first  instance,  I  was  much  affected  toward  it  by  reading  that  admirable 
work,  The  Bridgewater  Treatise  on  Geology,  written  by  the  Rev.  Dr.  Buckland, 
in  which  he  describes  the  teeth  of  that  gigantic  saurian,  and  so  graphically  com- 
pares them  to  the  combination  of  knife,  saw  and  scimeter,  which,  with  the  fossil 
fragment  of  the  jaw  in  my  hand,  could  not  fail  to  impress  me  with  a  precise  idea 
of  the  manner  in  which  this  creature  devoured  its  prey.  He  did  not  snap  and 
swallow  like  an  alligator,  but  did,  with  tooth  and  claw,  cut  off  and  tear  the  flesh 
of  his  victim,  like  the  lion  or  tiger.  The  fragment  of  the  jaw  also  gave  a  definite 
conception  of  the  dimensions  of  the  head,  and  explained  the  necessity  for  the 
animal  to  have  an  active  power  over  the  formidable  weapons  with  which  he  con- 
quered and  devoured  his  prey.  To  do  this  successfully,  it  was  necessary  for  the 
strong  tendon  attached  to  the  back  of  the  head  to  be  also  firmly  anchored  at  its 
other  extremity  to  the  long  spines  of  the  nerve-arches  at  the  junction  of  the  neck 
and  back,  as  in  the  horse,  stag,  elephant,  tiger,  and  all  animals  having  an  active 
use  for  a  large  and  heavy  head.  This  theoretical  reasoning  and  conviction  1  em- 
bodied  in  a  preliminary  sketch  with  the  elevated  ridge  on  the  fore  part  -of  the 
back,  to  submit  to  the  learned  savans  whorr*  I  had  the  privilege  of  consulting  at 
that  time,  and  by  whom  it  was  condemned  as  exceptional  in  the  case  of  reptiles, 
My  convictions,  however,  were  too  strong  to  allow  me  to  yield  to  their  decision, 
I  therefore  commenced  this  gigantic  model  in  the  spring  of  the  year  1854,  and 
completed  it  the  ioth  June  of  the  same  year. 

The  supposititious  hump-like  ridge  continued  to  excite  various  criticisms  as  to 
its  probability.  At  the  end  of  the  same  year  I  had  the  pleasure  of  receiving  a 
visit  from  Prof.  Richard  Owen  to  congratulate  me  on  the  discovery  in  the 
Wealden  sandstone,  Sussex,  of  the  bones  which  justified  the  exceptional  fqrtn^ 
which  I  had  predicated." 


Q  UESTIONS. 

187.  Describe  the  disturbances  that  marked  the  close  of  the 
Jurassic  Period.  What  noted  scenery  is  of  this  era?  Location  ot 
the  cretaceous  rocks  ?  Kinds  of  rock  ? 

188-9.  Describe  the  "  green-sand  "  of  New  Jersey.  What  is  said 
of  the  cretaceous  coal-beds?  Appearance  of  chalk  under  the  mi- 
croscope? What  is  said  of  rhizopods?  Curious  story  told  of 
Ehrenberg  ? 

190.  What  is  said  of  the  deep-sea  dredgings  ?  Are  we  not  now 
living,  in  a  certain  sense,  in  the  Cretaceous  Period  ?  Are  the 
American  fossils  of  this  period  different  from  the  English?  Why? 

191-4.  Describe  the  cimoliasaur.  The  mosasaur.  The  snapping- 
turtles.  The  crocodiles.  The  dinosaurs.  The  hadrosaur.  The 
Iselaps. 

Describe  the  great  disturbances  which  took  place  at  the  close  of 
ihe  Mesozoic  Age.  Cause. 

CENOZOIC  TIME. — Name  its  periods.    Its  general  characteristics. 

196.  Its  geography.     The  epochs  of  the  Tertiary  Period.     Origin 
of  the  term  "  Tertiary."     Geological  condition  of  Europe.     Euro- 
pean divisions  of  the  Tertiary. 

197.  Location  of  the  Tertiary  rocks.     How  do  we  determine  the 
way  in  which  its  deposits  were  formed  ?     Describe  the  "  pine  bar' 
rens."     Extent  of  Tertiary  rocks  on  the  Pacific  coast. 

198.  Kinds  of  rock.      What  is  nummulitic  limestone  ?     Where 
found  ?    The  Tertiary  coal-beds?     Is  coal  found  below  the  Carbon- 
iferous rocks?     Above?     What  is  said  of  the  abundant  vegetation? 

199-202.  What  peculiar  kinds  of  plants,  not  belonging  to  those 
regions  at  present,  are  found  fossil  ?  What  do  they  teach  ?  How 
many  species  of  Tertiary  shells?  Their  appearance?  Name  the 
various  kinds  of  animal  remains.  What  is  said  of  the  insects 
found  ?  *  Describe  the  zeuglodon. 


*  The  story  that  these  beds  tell  seems  to  be  this :  A  large  fresh-water  or  brack- 
ish lake  existed,  covering  a  considerable  portion  of  western  Colorado  and  eastern 
Utah.  Streams  carried  down  fine  sediment  and  free  petroleum,  from  numerous 
springs  in  the  surrounding  country,  for  ages ;  the  petroleum  increased  in  flow 
until  the  sediment  of  the  lake  became  thoroughly  charged  with  it,  and  the  can- 
nelite  was  the  result.  A  change  in  the  level  of  the  country  and  the  course  of  the 
streams  is  indicated  by  the  overlying  sandstones  and  conglomerates,  nearly  desti- 
tute of  petroleum,  and  at  least  one  thousand  feet  in  thickness.  During  the  time 
that  this  immense  amount  of  sediment  was  being  deposited,  willows,  maples, 


QUESTIONS. 

203.  Give  an  account  of  the  discoveries  made  by  Cuvier  in  the 
Paris  basin. 

204.  What  was  probably  the  character  of  this  region  at  that  time  ? 
Describe  the  paleotherium.    How  do  we  know  that  flowers  existed 
in  the  Tertiary  Period  ? 

205.  What  is  said  of  the  Bad  Lands?     Where  are  they?     What 
fossils    do    they  contain  ?     What   animals,   since   domesticated  by 
man,  inhabited  the  shores  of  that  Tertiary  sea  ?  *      Describe   the 
titanotherium. 

206.  What  was  the  probable  origin  of  this  region  ?     Were  there 
probably  more  than  one  of  those  great  fresh-water  lakes  in  the 
Tertiary  Period? 

207.  Name  the  epochs  of  the  Post-Tertiary.     Condition  of  the 
continent  at  this  time.     What  change  ensues  ? 

208.  What  is  the  Drift  ?     Its  extent?    What  is  said  of  bowlders — 
their  size  and  appearance  ? 

209.  From  what  direction  did  they  come  ?     Illustrate. 

210.  What  are  lost  rocks  ?     Why  are  bowlders  more  abundant  at 
the  east  than  at  the  west  ?     What  are  glacial  striae  ?     Describe  their 
appearance.     What  is  their  general  direction?     On  which  side  of 
mountains  are  they  found  ? 

212.  How  high   do   they   extend  ?     Describe   the   formation   of 
glaciers  in  Alpine  valleys. 

215.  Define  the  different  kinds  of  moraines.     Tell  how  blocks 
are  conveyed  to  a  distance.     How  striae  are  cut. 


oaks,  and  many  strange  trees  grew  on  the  land,  palaeotheres  and  turtles  swam  in 
the  waters,  and  clouds  of  insects  sported  over  its  surface.  The  bitumen  seems  to 
have  flowed  from  the  shales  as  petroleum  after  their  upheaval,  and  to  have  hard- 
ened in  time  into  its  present  form.  The  character  of  the  ancient  vegetation  is 
shown  by  the  fossil  wood  found  in  great  abundance. — Proc.  Boston  Soc.  of  Nat. 
History,  1866. 

*  "  Tt  is  a  marvelous  fact  in  the  history  of  mammalia  that  in  South  America  a 
native  horse  should  have  lived  and  disappeared,  to  be  succeeded  in  after  years  by 
countless  herds  descended  from  the  few  introduced  by  the  Spanish  colonists." 
(Darwin.)  These  domestic  animals,  which  were  then  native  in  America,  were 
not  of  exactly  the  same  species  as  those  now  used  by  man.  The  fossil  remains  of 
a  horse  have  been  found  at  the  west,  which,  when  alive,  could  not  have  been 
three  feet  high.  Horses  had  entirely  disappeared  from  the  continent  when  the 
Spaniards  landed ,  and  the  Indians  supposed  man  and  beast  to  be  one  animal 


QUESTIONS . 

216.  Name  the  evidences  of  former  glaciers.  Describe  the  great 
glacier  on  the  coast  of  Greenland. 

217-18.  How  are  icebergs  formed?  What  effect  do  they  have  in 
the  transportation  of  rock  and  formation  of  striae  ?  Describe  the 
origin  of  the  glaciers  of  the  Drift  epoch.  Cause  of  the  cold.* 
The  effects. 

219.  What  change  occurred  in  the  Champlain  Epoch?  Its  effect? 
What  proof  have  we  that  river-channels  were  filled  by  these 
glaciers  ? 

220-21.  Effect  of  the  glacier-streams  ?  How  does  the  coarseness 
of  the  Drift  vary?  Effects  of  this  change?  Describe  the  continen- 
tal elevation  which  took  place  at  the  beginning  of  the  Terrace 
Epoch.  Its  effect  ?  Was  the  elevation  uniform  and  steady  ? 

222.  What  are  the  proofs  of  these  oscillations  ? 

223-4.  How  were  terraces  formed  ?  Which  were  made  in  the 
Champlain  Epoch?  The  Terrace?  What  are  ancient  sea-beaches? 
How  are  they  known  ?  How  high  are  they  found  ? 

225-6.  Localities  of  Post-Tertiary  fossils?  Do  they  resemble 
modern  species  ?  What  animals  led  the  life  of  the  period  ?  Name 
the  principal  quadrupeds  Describe  the  mammoth. 


*  There  is  a  growing  conviction  that  the  cause  of  this  glacial  cold  must  be 
sought  among  astronomical  phenomena.  It  has  been  suggested,  i.  That  we  are 
now  moving  through  a  comparatively  starless,  and  hence  cheerless,  region  ot 
space  ;  and  that  as  the  earth  passes  from  densely  to  thinly-clustered  portions,  and 
vice  versa,  the  heat  received  and  consequent  temperature  must  vary  ;  2.  That 
the  axis  of  the  earth  may  not  have  always  pointed  in  the  same  direction  or  at  the 
same  angle  as  now,  and  that  any  variation  would  have  produced  a  change  of  cli- 
mate ;  3.  That  during  the  Great  Year  of  the  astronomers,  about  21,000  common 
years,  each  hemisphere  has  two  seasons  (see  Astronomy,  page  121,  et  seg.}.  Dur- 
ing half  of  this  time  the  northern  hemisphere  has  its  summer  in  aphelion,  and 
winter  in  perihelion ;  while  in  the  other  half  this  is  reversed.  When  the  Great 
Winter  prevails  at  the  north  pole,  there  is  an  accumulation  of  ice  and  snow. 
This  changes  the  center  of  gravity  of  the  earth.  The  water  will  flow  thither  to 
adjust  the  equilibrium,  and  thus  overflow  a  part  of  the  northern  hemisphere. 
These  Great  Summers  and  Winters,  with  their  accumulations  of  snow  and  ice, 
and  consequent  submergence  of  the  land,  have  occurred,  it  is  thought,  alternately 
at  either  pole  at  intervals  of  about  10,500  years  through  all  the  past.  In  the  year 
1250  (see  Astronomy,  p.  129)  the  Great  Winter  terminated  at  toe  soutn  poie, 
where  foi  1-2,500  years  these  accumulations  had  been  gathering.  In  the  same 
vear  the  Great  Northerr:  Sum.ner  culminated.  The  hemisphere  which  has  its 
winter  ;n  anbeuoa  is  not  onlv  further  from  tn %  sun.  tout  has  a  winter  of  eicht  davs 


QUESTIONS.  273 

227.  The  locality  of  fossil  ivory  in  Siberia  ?  What  curious  legend 
have  the  Tartars  ?    Describe  the  discovery  of  a  mammoth  preserved 
in  ice. 

228.  The   mastodon.      How   can   mastodon  remains  be   distin- 
guished from  those  of  the  elephant? 

229.  What  was  the  mastodon's  food?     How  is  this  known?     De- 
scribe the  megatherium.     What  was  its  food  ?     Uses  of  its  tail ' 
Was  its  structure  adapted  to  its  life  ? 

230-4,  Describe  the  glyptodon.  The  Irish  elk.  The  cave-beai, 
Why  so  named  ?  The  hyena.  Discovery  of  the  Kirkdale  cave. 

236.  What  is  said  by  Whitney  of  the  Glacial  Epoch  in  California  ? 
Is  any  Drift  found  in  Oregon  ? 

237.  Origin  of  canons.     What  is  the  Loess  of  the  Nile?     The 
Rhine?     The  Mississippi  valley? 

238.  Its  location  and  appearance?     Its  fossils?    What  are  sand- 
dunes  ?     Where  found  ?     How  formed  ? 

THE  ERA  OF  MIND. — Does  Geology  tell  when  man  appeared? 
Where  are  his  remains  found  ? 

244-7.  Name  the  classifications  of  these  primeval  remains 
What  do  these  terms  indicate?  Were  these  ages  coeval?  De- 
scribe the  man  of  the  Stone  Age  in  the  first  epoch.  The  second 
epoch.  The  third  epoch. 

248-9.  Influence  of  the  metals  in  advancing  civilization  ?  What 
metals  were  first  used  ? 

250.  Describe  man's  progress  in  the  Bronze  epoch.  The  Iron 
epoch. 

longer  duration  (Astronomy,  p.  118).  M.  Adhemar  has  worked  out  this  theory 
very  fully.  He  claims,  however,  that  owing  to  the  movement  in  the  Earth's 
orbit  (Astronomy,  p.  128),  the  Great  Year  is  only  21,000  years  long  ;  each  hemi- 
sphere having  a  summer  of  10,500  years  and  a  winter  of  equal  length.  The  Great 
Summer  of  the  northern  hemisphere  culminated,  according  to  his  calculations,  1248 
B.C.  Since  that  date  our  Great  Winter  has  been  in  progress.  Our  pole,  in  its 
turn,  goes  on  getting  cooler  continually ;  ice  is  being  heaped  upon  snow,  and 
snow  upon  ice,  and  in  seven  thousand  three  hundred  and  eighty-eight  years  the 
center  of  gravity  of  the  earth  will  return  to  its  normal  position,  which  is  the 
geometrical  center  of  the  spheroid.  Following  the  immutable  laws  of  central 
attraction,  the  southern  waters  accruing  from  the  melted  ice  and  snow  of  the 
south  pole  will  return  to  invade  and  overwhelm  once  more  the  continents  of  the 
northern  hemisphere,  giving  rise  to  new  continents,  in  all  probability,  in  the 
southern  hemisphere. 


A  TRIASSIC  FISH. 


Eurinotus  ceratocephalus. 


ACALEPH,  Ak'-a-lef. 
AGATE,  Ag'-ate. 
ALBITE,  Al'-ffite. 
ALUMINA,  A-lu'-me-na,. 
ALUMINIUM,  Al-U-min'-e-um. 
AMETHYST,  Am'-e-thyst. 
AMYGDALOID,  A-mlg'-da-loid. 
ANOPLOTHEBIUM,  An-o-plo-the'-re-um. 
ARGILLACEOUS,  Ar-fil-a'-shus. 
ASBESTOS,  As-bes'-tus. 
ASTEROPHYLLITE,  As-Ur-off'-e-lite. 
AUGITE,  Aw'-jlte. 

BASALT,  Ba-sawlV. 
BELEMNITE,  Be-lem'-rilte. 
BRACHIOPOD,  Brack'-e-o-pod. 
BRYOZOAN,  Bri-o-zo'-an. 

CALAMITE,  Kal'-a-mite. 
CEPHALASPIS,  Sef-a-las'-pis. 
CEPHALOPOD,  Sef'-ctt-o-pod. 
CHALCEDONY,  Kal-s$d'-o-ny. 
CHRYSOPRASE,  Krys'-o-prase. 
COCCOSTEUS,  Koc-cos'-te-us. 
CONCHOIDAL,  Kon-koi'-dal. 
CONGLOMERATE,  Kon-glom'-e-rate. 
CONIFER,  Ko'-ni-fer. 
CORAL,  Kor'-al. 
CRETACEOUS,  Kre-ta'-shus, 
CRINOID,  Krl-noid. 
CRUSTACEAN,  Krus-ta'-sfie-an. 
CYCAD,  Sy'-kad. 

DEVONIAN,  De-v5'-ne-an, 
DINOSAUR,  Di'-no-sawr. 
DINOTHERIUM,  Di'-no-the'-re-um. 
DODECAHEDRON,  Do-dec-d-he'-dron. 


DOLOMITE,  Dol'-o^nite ;  (Dolomien.  a 

French  geologist.) 
DOLERITE,  Dol'-e-rite. 

ECHINODERM,  E-kin'-o-derm. 
ECHINOIDS,  Ek-i-noids. 
ENCRINITE,  En'-kre-nite. 
ENDOGEN,  En'-do-jen. 
EURYPTERUS,  Eu-ryp'-te-rus. 
EOCENE,  E'-o-seen, 
EQUISETACE^:,  E-que-se-ta'-she-e. 
EQUISETUM,  Eq-ue-se'-tum. 
EXOGEN,  Ex'-o-jen. 
EozoQN,  E-o-zo'-an. 

FAUNA,  Fawn' -a. 
FELDSPAR,  Feld'-spar. 
FORAMINIFERA,  Fo-ram-m-if-er-a. 

GANOID,  Ga'-noid. 
GASTEROPOD,  Gas'-ter-o-pod. 
GEODE,  Je'-5de. 
GLACIER,  Ola-seer. 
GNEISS,  Nice. 
GONIATITE,  Go'-ni-a-tite. 
.GRANITE,  Gran'-it. 
GRAPTOLITE,  Grap'-to-lite. 
GYPSUM,  Jip'-sum. 

HADROSAUR,  Ha'-dro-sawr. 
HIPPOPOTAMUS,  Hip-po-p8t'-a-mu8. 
HOLOPTYCHIUS,  Hol-op-tik'-e-us. 
HORNBLENDE,  Horn-blende. 
HYL.EOSAUR,  Hy'-k-o-sawr. 

ICHTHYOSAUR,  Ich'-the-o-sawr. 
IGNEOUS,  Ig'-ne-us. 


GLOSSARY. 


IGUANODON,  Ig-wdn'-o-don. 
INFUSORIA,  In-fu-zo'-re-a. 

LAMELLIBRANCHIATE,  Ld-mel-e-brank'- 

e-ate. 

LEPIDODENDBON,  Lep-e-do-den'-dron. 
LIAS,  Li'-as. 
LIGNITE,  Lig-mte. 

MASTODON,  Mas'-to-dm. 
MEGALOSAUB,  Meg'-a-lo-sawr. 
MEGATHERIUM,  Meg-a-the'-re-um. 
METAMOBPHIC,  Met-a-mor'-phic. 
MIOCENE,  Mi'-o-seen. 
MOLLUSCA,  Mol-lm'-ca. 
MORAINE,  Mo-rain'. 
MOSASAUR,  Mo'-sa-sawr. 

NODULE,  Nod'-ule. 
NUMMULITE,  Num'-mu-ftte. 

ONTX,  O'-nix. 
OOLITE,  O'-o-tite. 
ORTHOCERATITE,  Or-tho-cer-a-ttte. 

PALEONTOLOGY,  Pal-e-on-tol'-o-gy. 
PALEOTHERIUM,  Pal-e-o-the'-re-wn. 
PALEOZOIC,  Pal'-e-o-zo4c. 
PLESIOSAUR,  PU'-sl-o-sawr. 
PLIOCENE,  Pli'-o-seen. 
PORPHYRY,  Por'-fe-ry. 
PROTOZOAN,  Pro-tozo'-an. 
PTERICHTHYS,  Ter-ik'-thys. 
PTKBODACTYLE,  Ter-ro-dacf-tyl. 


PTEROPOD,  Ter'-ro-pod. 
PYRITES,  Py-ri'-teez. 
PYROXENE,  Plr-ox'-een. 

QUARTZ,  Kworts. 

RHIZOPOD,  ttz'-o-pod. 
RAMPHORHYNCUS,  Bam-forWin'-kut. 

SAURIAN,  Sdw'-ri-an. 
SELENITE,  SZl'-en-ite. 
SERPENTINE,  Ser'-pen-fine 
SIGILLARIA,  Sig'-il-la'-re-a. 
SILURIAN,  Si-lu'-re-an. 
SIPHUNCLE,  SR-fvnk-kl. 
STALACTITE,  Std-lac'-ttte. 
STALAGMITE,  Std-ldg'-mite. 
STEATITE,  Ste'-a-tite. 
STIGMARIA,  Stig-md'-re-a. 
STRIA,  Strl-a. 
SYENITE,  Si'-en-ite. 

TALC,  Talc. 

TENTACULITES,  Ten'-tac-u-litf. 
TOURMALINE,  Toor'-ma-Vin. 
TRACHYTE,  Trd'-kite. 
TRILOBITE,  Tn'-lo-ffite. 
TUFA,  Tu'-fa. 

VERD-ANTIQUE,  Verd-an-teek'. 
VERTEBRA,  Ver'-te-bre. 

WEALDEN,  Weeld'-n. 
ZOOPHYTE,  Zt/-o-flt*. 


Boulders. 


Acadian  Epoch,  109. 

Acalephs  (Sea  Nettles)  107. 

Agate,  43. 

Alabaster,  53. 

Alhite,  53. 

Alluvial  Deposits,  237. 

Alumina,  48. 

Amethyst,  43. 

Ammonite,  171 

Amygdaloid,  60. 

Anoplotherium,  203. 

Appalachian  Beach,  131. 

Appalachian  Metamorphism,  164. 

Appalachian  Mountains,  110,  164. 

Appalachian  Kevolution,  163. 

Archaean,  99. 

Artesian  Wells,  21. 

Articulates,  132. 

Asbestos,  54. 

Athens  Marble,  124. 

Atmosphere,  112. 

Augite,  55. 

Azoic  Time,  98. 

Bad  Lands,  204. 

Basalt,  59. 

Basaltic  Pillars,  63. 

Beetle  Stones,  84. 

Belemnite,  172. 

Bird's  Eye  Limestone,  115. 

Bird  Tracks,  184. 

Black  River  Limestone,  115. 

Black  Slate,  141. 

Bloodstone,  45. 

Blue  Limestone  (Trenton  Epoch). 

Bog-iron  Ore,  102. 

Bowlders,  208. 

Brachiopods,  118. 


Breccia,  58. 
Bronze  Epoch,  249. 
Bryozoans  (Moss-animal). 
Buhrstone,  46. 

Calamites,  156. 
Calc  Spar,  49. 
Calcite,  49. 
Cameo,  44. 
Camel,  240. 

Canadian  Divisions,  99. 
Calciferous  Epoch,  110. 
Cambrian  Period,  107. 
Canadian  Epoch,  110. 
Cafion,  236. 
Carbuncle,  56. 
Carboniferous  Age,  149. 
Carboniferous  Period,  154. 
Carnelian,  43. 
Catskill  Period,  144. 
Cauda-Galli  Grit,  138. 
Cave  Bear,  230. 
Cenozoic  Time,  194. 
Cephalaspis,  137. 
Cephalopods,  118. 
Chalcedony,  43. 
Chalk,  49,  189. 
Chazy  Group,  115. 
Champlain  Epoch,  219. 
Chemung  Period,  143. 
Chert,  124, 139. 
Chlorite,  56,  75. 
Chronology,  30. 
Chrysoprase,  43. 
Chrysolite,  59. 
Cimoliasaur,  190. 
Cincinnati  Limestone,  121, 
Clay,  53. 


INDEX. 


Clay  Stones,  83. 

Cleavage,  41. 

Cliff  Limestone,  140. 

Clinton  Group,  124. 

Clinkstone,  53. 

Coal,  155. 

Coccosteus,  136. 

Comprehensive  Type,  137. 

Conchifers,  141. 

Concretions,  83. 

Conglomerate,  57. 

Conifers,  157. 

Continent,  Outlines  of,  104, 108. 

Coprolites,  174. 

Coral,  113. 

Corniferous  Period,  138. 

Corundum,  49. 

Cretaceous  Period,  187. 

Crinoids,  125. 

Crocodiles,  191. 

Crust  of  Earth,  21. 

Crustaceans,  109. 

Cycad,  170. 

Denudation,  82. 

Deep-Sea  Dredgings,  190. 

Development  Hypothesis,  251- 

Devonian  Age,  134 

Diatoms,  47. 

Dikes,  86. 

Dinoceras,  205. 

Dinosaur,  181, 191. 

Diorite,  60. 

Dip,  78. 

Diverse  Stratification,  79. 

Dislocations  of  Strata,  76. 

Dolomite,  51. 

Dolerite,  59. 

Drift  Epoch,  207. 

Dye  Stone,  124. 

Earthquakes,  23. 
Elasmosaur,  190. 
Elephant,  227. 
Emery,  49. 
Eocene,  196. 
Eozoic  Time,  98.         * 
Escarpment,  78. 
Eurypterus,  129. 
EozoOn  Canadense,  102. 

Faults,  80. 
Feldspar,  53. 
Fingal's  Cave.  61. 


Flint,  46. 
Folds,  81. 
Fossil,  27. 
Fossil  Farina,  48. 
Fucoids,  117. 

Galena  Limestone,  116. 
Ganoids,  135-6. 
Garnet,  56. 
Gasteropoda,  117. 
Genesee  Slate,  141. 
Geodes,  84. 

Geology,  Definition  of,  20. 
Geysers,  22. 
Glacial  Epoch,  207. 
Glacial  Striae,  210. 
Glaciers,  29,  212. 
Glyptodon,  230. 
Gneiss,  72. 
Gold  Rocks,  186. 
Goniatite,  141. 
Granite,  67. 
Graptolite,  121. 
Green  Mountains,  122, 131. 
Greenstone,  59. 
Gypsum,  52, 128. 

Hadrosaur,  191. 
Hall,  James,  107. 
Hamilton  Period,  139. 
Helderberg  Period,  138. 
Helderberg,  Lower,  128. 
Herkimer  Shales,  120. 
Holoptychius,  137. 
Hornstone,  46. 
Hornblende,  54. 
Horse,  239,  250,  271. 
Hot  Springs,  22. 
Hudson  Period,  120. 
Hyena,  232. 

Iceberg,  217. 
Ichthyosaur,  173. 
Iguanodon,  181. 
Igneous  Rocks,  26,  59. 
Infusorial  Earth,  48. 
Iron  Epoch,  250. 
Ironstone,  59. 
Irish  Elk,  231. 
Isinglass,  54. 

Jasper,  45. 

Jointed  Structure,  81. 

Jurassic,  167. 


INDEX. 


279 


Kaolin,  54. 

Kitchen  Middens,  247. 

Labradorite,  53. 

Lafiyrinthodon,  183. 

Laelaps,  192. 

Lake  Bottom,  81. 

Lake  Dwellings,  349. 

Lake  Superior,  113. 

Lamellibranch,  141. 

Lamina,  78. 

Laurentian  Mountains,  103. 

Lava,  65. 

Lepidodendron^  157. 

Lias,  168. 

Limestone,  49,  58. 

Lingula,  110. 

Lithological  Geology,  35. 

Loess,  237. 

Loraine  Shales,  120. 

Lower  Magnesian  Limestone,  110. 

Mammoth  Cave,  153. 

Mammoth,  225. 

Man,  Coming  of,  243. 

Map  of  Eozoic  Time,  100. 

Map  of  Mesozoic  Time,  168. 

Map  of  Cenozoic  Time,  195. 

Marble,  51,  75. 

Marble,  Carrara,  67. 

Marl,  50. 

Marcellus  Shale,  140. 

Mastodon,  228. 

Medina  Group,  123. 

Megalosaur,  182. 

Megatherium,  229. 

Mesozoic  Time,  166. 

Metal  Age,  248. 

Metamorphism,  66,  88, 164. 

Metamorphic  Rocks,  66. 

Methods  of  Geological  Study,  23. 

Mica,  54. 

Mica  Schist,  74. 

Millstone  Grit,  154. 

Miocene,  196. 

Montmorency  Falls,  104. 

Mound  Limestone,  124. 

Mountains,  103. 

Mollusks,  109. 

Mosaic  Account,  19, 105, 114,  238. 

Nature,  Uniformity  of,  23- 
Nebular  Hypothesis,  17. 


Niagara  Limestone,  124. 
Nummulitic  Limestone,  198. 

Obsidian,  66. 

Offsets,  80. 

Old  Red  Sandstone,  135. 

Oneida  Epoch,  123. 

Onondaga  Group,  139. 

Onyx,  44. 

OOlite,  50, 168. 

Opal,  45. 

Oriskany  Period,  130. 

Orthoceratite,  118. 

Ostrea  Marshii,  170. 

Outcrop,  77. 

Oyster,  170. 

Paleozoic  Time,  106. 
Paleotherium,  203. 
Paradoxides,  109. 
Pentamerus,  ]29. 
Permian,  162. 
Phacops  bufo,  143. 
Pine  Barrens,  197. 
Plaster,  52. 
Plesiosaur,  177. 
Pliocene,  196. 
Porphyry,  60. 
Post-Tertiary,  207. 
Potsdam,  109. 
Portage  Group,  143. 
Primeval  Man,  243. 
Pterodactyle,  178. 
Pterichthys,  136. 
Pudding-stone,  58. 
Pumice,  66. 
Pyroxene,  55. 

Quartz,  40. 
Quartzite,  75. 
Quaternary  Epoch,  207. 
Quincy  Granite,  74. 

Radiates,  112. 
Ramphorhynchus,  183. 
Reindeer  Epoch,  245. 
Rhizopods,  102,  188. 
Rhinoceros,  239. 
Rocky  Mountains,  122. 
Rocks,  Classification  of,  57. 
Rocks,  Composition  of,  40. 
Rocks,  Metamorphic,  66.    . 
Rocks,  Sedimentary,  57. 
Rocks,  Structure  of,  75. 


880 


INDEX. 


Rocks,  Stratified,  57,  76. 
Rocks,  Trap,  59. 
Rocks,  Unstratified,  59,  85. 
Rocks,  Volcanic,  65. 

Salina  Period,  127. 
Salt  Springs,  128. 
Salt  Beds,  186. 
Sand,  46. 
Sand  Dunes,  238. 
Sandstone,  57. 
Sapphire,  49. 
Sard,  43. 
Satin  Spar,  53. 

Scenic  Description,  20,  58,  60,  66,  70, 
73,  74,  106,  132,  145, 161,  192,  239. 
Schoharie  Grit,  138. 
Scoria,  66. 

Sculptured  Rocks,  114. 
Sea-weeds,  106, 117. 
Sea-pens,  121. 
Sedimentary  Rocks,  24,  57. 
Selenite,  53. 
Septaria,  83. 
Serpentine,  56. 
Shale,  58. 

Shawangunk  (Shong'-gum)  Grit,  123. 
Sigillaria,  157. 
Silica,  40. 
Silicates,  53. 
Silurian  Age,  107. 
Sink-holes,  153. 
Siphuncle,  120. 
Slate,  75,  85. 

Solenhofen  Limestone,  169. 
Soapstone,  55. 
Spirifer  arenosus,  131. 
Spirifer  mucronatus,  141. 
Stalactites,  50. 
Stalagmites,  50. 


Steatite,  55. 

St.  Peter's  Sandstone,  115. 

Stone  Age,  244. 

Stratified  Rocks,  57. 

Stratum,  78. 

Subcarboniferous  Period,  152. 

Syenite,  74. 

Talc,  55. 

Talcose  Schist,  75. 
Tentaculite,  129. 
Tertiary  Period,  196. 
Terrace  Epoch,  221. 
Theory,  Value  of  a,  252. 
Titanotherium,  205. 
Touchstone,  45. 
Tourmaline,  56. 
Trap-rock,  59. 
Trachyte,  65. 
Travertine,  49. 
Trenton  Period,  115. 
Trilobite,  111. 
Triassic  Period,  167. 
Tufa,  49. 

Tully  Limestone,  140. 
Turtles,  191. 

Uniformity  of  Nature,  23, 132. 
Upper  Helderberg  Period,  138. 
Utica  Slate,  120. 

Veins,  86. 
Verd-antique,  51. 

Water  Lime  Group,  128. 
Wealden,  168. 

Xiphodon,  203. 
Zeuglodon,  202. 


Atoll  with  its  fringe  of  ooooanut  trees  and  la«oon  within, 


THE  NATIONAL   SERIES  OF  STANDARD  SCHOOL-BOOKS. 


BARNES'S   ONE-TERM    HISTORY 
SERIES. 


Brief     History    of    the    United 
States. 

This  is  probably  the  MOST  ORIGINAL  SCHOOL-BOOK  pub- 
lished for  many  years,  in  any  department.  A  few  of  it? 
claims  are  the  following  :  — 

1.  Brevity.  —  The  text  is  complete  for  grammar  school 
or  intermediate  classes,  in  290   12mo  pages,  large  type. 
It  may  readily  be  completed,  if  desired,  in  one  term  of 
study. 

2.  Comprehensiveness.  —  Though  so  brief,  this  book 
contains  the  pith  of  all  the  wearying  contents  of  the  larger 
manuals,  and  a  great  deal  more  than  the  memory  usually 
retains  from  the  latter. 

3.  Interest  has  been  a  prime  consideration.     Small 

books  have  heretofore  been  bare,  full  of  dry  statistics,   unattractive.    This  one  is 
charmingly  written,  replete  with  anecdote,  and  brilliant  with  illustration. 

4.  Proportion  of  Events.  —  It  is  remarkable  for  the  discrimination  with  which 
the  different  portions  of  our  history  are  presented  according  to  their  importance.     Thus 
the  older  works,  being  already  large  books  when  the  Civil  War  took  place,  give  it  less 
space  than  that  accorded  to  the  Revolution. 

5.  Arrangement.  — In  six  epochs,  entitled  respectively,  Discovery  and  Settlement, 
the  Colonies,  the  Revolution,  Growth  of  States,  the  Civil  War,  and  Current  Events. 

6.  Catch  Words.  —  Each  paragraph  is  preceded  by  its  leading  thought  in  promi- 
nent type,  standing  in  the  student's  mind  for  the  whole  paragraph. 

7.  Key  Notes.  —  Analogous  with  this  is  the  idea  of  grouping  battles,  &c.,  about 
some  central  event,  which  relieves  the  sameness  so  common  in  such  descriptions,  and 
renders  each  distinct  by  some  striking  peculiarity  of  its  own. 

8.  Fopt-Notes. — These  are  crowded  with  interesting  matter  that  is  not  strictly  a 
part  of  history  proper.     They  may  be  learned  or  not,  at  pleasure.     They  are  certain 
in  any  event  to  be  read. 

9.  Biographies  of  all  the  leading  characters  are  given  in  full  in  foot-notes. 

10.  Maps.  —  Elegant  and  distinct  maps  from  engravings  on  copper-plate,  and  beauti- 
fully colored,  precede  each  epoch,  and  contain  all  the  places  named. 

11.  Questions  are  at  the  back  of  the  book,  to  compel  a  more  independent  use  of  the 
text.    Both  text  and  questions  are  so  worded  that  the  pupil  must  give  intelligent 
answers  IN  HIS  OWN  WORDS.     "  Yes  "  and  "  No  "  will  not  do. 


THE  NATIONAL   SERIES  OF  STANDARD   SCHOOL-BOOKS. 


HISTORY  —  Continued. 

12.  Historical  Recreations.  — These  are  additional  questions  to  test  the  student's 
knowledge,  in  review,  as:    "What  trees  are  celebrated   in  our  history?"    "When 
did  a  fog  save  our  army?"     "What  Presidents  died  in  office?"     "When  was  th« 
Mississippi  our  western   boundary?"     "Who  said,    'I  would  rather  be  right  than 
President '  ? "  &c. 

13.  The  Illustrations,  about  seventy  in  number,  are  the  work  of  our  best  artists 
and  engravers,  produced  at  great  expense.     They  are  vivid  and  interesting,  and  mostly 
upon  subjects  never  before  illustrated  in  a  school-book. 

14.  Dates.  — Only  the  leading  dates  are  given  in  the  text,  and  these  are  so  associated 
as  to  assist  the  memory,  but  at  the  head  of  each  page  is  the  date  of  the  event  first 
mentioned,  and  at  the  close  of  each  epoch  a  summary  of  events  and  dates. 

15.  The  Philosophy  of    History  is   studiously  exhibited,  the   causes  and  effects 
of  events  being  distinctly  traced  and  their  inter-connection  shown. 

16.  Impartiality.  —  All  sectional,   partisan,  or  denominational  views  are  avoided. 
Facts  are  stated  after  a  careful  comparison  of  all  authorities  without  the  least  prejudice 
or  favor. 

17.  Index.  —  A  verbal  index  at  the  close  of  the  book  perfects  it  as  a  work  of  reference. 
It  will  be  observed  that  the  above  are  all  particulars  in  which  School  Histories  have 

been  signally  defective,  or  altogether  wanting.     Many  other  claims  to  favor  it  shares  in 
common  with  its  predecessors. 


TESTIMONIALS. 


From  PROF.  WM.    F.   ALLEN,   State   Uni- 
versity of  Wisconsin. 

"Two  features  that  I  like  very  much 
are  the  anecdotes  at  the  foot  of  the  page 
and  the  ' Historical  Recreations'  in  the 
Appendix  The  latter,  I  think,  is  quite 
a  new  feature,  and  the  other  is  very  well 
executed." 

From  HON.  NEWTON  BATEMAN,  Superin- 
tendent Public  Instruction,  Illinois. 
"Barnes's  One-Term  History  of  the 
United  States  is  an  exceedingly  attrac- 
tive and  spirited  little  book.  Its  claim 
to  several  new  and  valuable  features  seems 
well  founded.  Under  the  form  of  six  well- 
defined  epochs,  the  history  of  the  United 
States  is  traced  tersely,  yet  pithily,  from 
the  earliest  times  to  the  present  day.  A 
good  map  precedes  each  epooh,  wlrereby 
the  history  and  geography  of  the  period 
may  be  studied  together,  as  they  always 
should  be.  The  syllabus  of  each  paragraph 
is  made  to  stand  in  such  bold  relief,  by 
the  use  of  large,  heavy  type,  as  to  be  of 
much  mnemonic  value  to  the  student.  The 
book  is  written  in  a  sprightly  and  pi- 
quant style,  the  interest  never  flagging 
from  beginning  to  end,  —  a  rare  and  diffi- 
cult achievement  in  works  of  this  kind." 

From  HON.  ABNEB  J.   PHIPPS,    Superin- 
tendent Schools,  Lewiston,  Maine. 
"  Barnes's  History  of  the  United  States 


has  been  used  for  several  years  in  the 
Lewiston  schools,  and  has  proved  a  very 
satisfactory  work.  I  have  examined  the 
new  edition  of  it." 

From  HON.  E.  K.  BUCHELL,  City  Superin- 
tendent Schools,  Lancaster,  Pa. 

"  It  is  the  best  history  of  the  kind  I  have 
ever  seen." 

From    T.    J.    CHARLTON,    Superintendent 

Public  Schools,    Vincennes,  Ind. 
"We  have  used  it  here  for  six  years, 
and  it  has  given  almost  perfect  satisfac- 
tion. .  .  .  The  notes  in  fine  print  at  the 
bottom  of  the  pages  are  of  especial  value." 

From  PROF.   WM.    A.    MowRy,  E.  $•  C. 
School,   Providence,  R.  I. 

"  Permit  me  to  express  my  high  appre- 
ciation of  your  book.  I  wish  all  text- 
books for  the  young  had  equal  merit." 

From  HON.  A.  M.  KEILEY,  City  Attorney, 
Late  Mayor,  and  President  of  the  School 
Soard,  City  of  Richmond,  Va. 
"  I  do  not  hesitate  to  volunteer  to  you 
the  opinion  that  Barnes 's  History  is  en- 
titled to  the  preference  in  almost  every 
respect  that  distinguishes  a  good  school- 
book.  .  .  .  The  narrative  generally  exhibits 
the  temper  of  the  judge ;  rarely,  if  ever, 
of  the  advocate." 


25 


THE  NATIONAL   SERIES  OF  STANDARD   SCHOOL-BOOKS. 


A  Brief  History  of  An- 
cient Peoples. 


With  an  account  of  their  monuments, 
literature,  and  manners.  340  pages. 
12mo.  Profusely  illustrated. 

In  this  work  the  political  history, 
which  occupies  nearly,  if  not  all, 
the  ordinary  school  text,  is  condensed 
to  the  salient  and  essential  facts,  in 
order  to  give  room  for  a  clear  outline 
of  the  literature,  religion,  architecture, 
character,  habits,  &c.,  of  each  nation. 
Surely  it  is  as  important  to  knowsome- 
tff  about  Plato  as  all  about  Caesar, 
and  to  learn  how  the  ancients  wrote 
their  books  as  how  they  fought  their 
battles. 

The  chapters  on  Manners  and  Cus- 
toms and  the  Scenes  in  Real  Life  repre- 
sent the  people  of  history  as  men  and 
women  subject  to  the  same  wants,  hopes 
and  fears  as  ourselves,  and  so  bring  the  distant  past  near  to  us.  The  Scenes,  which  are 
intended  only  for  reading,  are  the  result  of  a  careful  study  of  the  unequalled  collections  of 
monuments  in  the  London  and  Berlin  Museums,  of  the  ruins  in  Rome  and  Pompeii,  and 
of  the  latest  authorities  on  the  domestic  life  of  ancient  peoples.  Though  intentionally 
written  in  a  semi-romantic  style,  they  axe  accurate  pictures  of  what  might  have  occurred, 
and  some  of  them  are  simple  transcriptions  of  the  details  sculptured  in,  Assyrian 
alabaster  or  painted  on  Egyptian  walls. 

26 


THE  NATIONAL   SERIES   OF  STANDARD   SCHOOL-BOOKS. 


HISTORY  —  Continued. 

The  extracts  made  from  the  sacred  books  of  the  East  are  not  specimens  of  their  style 
and  teachings,  but  only  gems  selected  often  from  a  mass  of  matter,  much  of  which  would 
be  absurd,  meaningless,  and  even  revolting.  It  has  not  seemed  best  to  cumber  a  book 
like  this  with  selections  conveying  no  moral  lesson. 

The  numerous  cross-references,  the  abundant  dates  in  parenthesis,  the  pronunciation 
of  the  names  in  the  Index,  the  choice  reading  references  at  the  close  of  each  general 
subject,  and  the  novel  Historical  Recreations  in  the  Appendix,  will  be  of  service  to 
teacher  and  pupil  alike. 

Though  designed  primarily  for  a  text-book,  a  large  class  of  persons  —  general  readers, 
who  desire  to  know  something  about  the  progress  of  historic  criticism  and  Lhe  recent 
discoveries  made  among  the  resurrected  monuments  of  the  East,  but  have  no  leisure  to 
read  the  ponderous  volumes  of  Brugsch,  Layard,  Grote,  Mommsen,  and  Ihne  —  will  find 
this  volume  just  what  they  need. 


From  HOMER  B.    SPRAGUE,  Head  Master 
Girls'  High  School,  West  Newton,  St.,  Bos- 
ton, Mass. 
"  I  beg  to  recommend  in  strong  terms 

the    adoption    of   Barnes's   'History    of 


Ancient  Peoples '  as  a  text-book.  It  is 
about  as  nearly  perfect  as  could  be 
hoped  for.  The  adoption  would  give 
great  relish  to  the  study  of  Ancient 
History." 


HE  Brief  History  of  France. 

By  the  author  of  the  "  Brhf  United  States," 
with  all  the  attractive  feattires  of  that  popu- 
lar work  (which  see)  and  new  ones  of  its  own. 
It  is  believed  that  the  History  of  France 
has  never  before  been  presented  in  such 
brief  compass,  and  this  is  effected  without 
sacrificing  one  particle  of  interest.  The  book 
reads  like  a  romance,  and,  while  drawing  the 

,     ,    .  student  by  an  irresistible  fascination  to  his 

task,  impresses  the  great  outlines  indelibly  upon  the  memory. 

27 


THE  NATIONAL   SERIES  OF  STANDARD   SCHOOL-BOOKS. 

DR.  STEELE'S  ONE-TERM  SERIES, 
IN  ALL  THE  SCIENCES. 

Steele's  i4-Weeks  Course  in  Chemistry. 
Steele's  i4-Weeks  Course  in  Astronomy. 
Steele's  i4-Weeks  Course  in  Physics. 
Steele's  i4-Weeks  Course  in  Geology. 
Steele's  i4-Weeks  Course  in  Physiology. 
Steele's  i4-Weeks  Course  in  Zoology. 
Steele's  i4-Weeks  Course  in  Botany. 

Our  text-books  in  these  studies  are,  as  a  general  thing,  dull  and  uninteresting. 
They  contain  from  400  to  600  pages  of  dry  facts  arid  unconnected  details.  They  abound 
in  that  which  the  student  cannot  learn,  much  less  remember.  The  pupil  commences 
the  study,  is  confused  by  the  fine  print  and  coarse  print,  and  neither  knowing  exactly 
what  to  learn  nor  what  to  hasten  over,  is  "crowded  through  the  single  term  generally 
assigned  to  each  branch,  and  frequently  comes  to  the  close  without  a  definite  and  exact 
idea  of  a  single  scientific  principle. 

Steele's  "  Fourteen-Weeks  Courses  "  contain  only  that  which  every  well-informed  per- 
son should  know,  while  all  that  which  concerns  only  the  professional  scientist  is  omitted. 
The  language  is  clear,  simple,  and  interesting,  and  the  illustrations  bring  the  subject 
within  the  range  of  home  life  and  daily  experience.  They  give  such  of  the  general 
principles  and  the  prominent  facts  as  a  pupil  can  make  familiar  as  household  words 
within  a  single  term.  The  type  is  large  and  open  ;  there  is  no  fine  print  to  annoy ; 
the  cuts  are  copies  of  genuine  experiments  or  natural  phenomena,  and  are  of  fine 
execution. 

In  fine,  by  a  system  of  condensation  peculiarly  his  own,  the  author  reduces  each 
branch  to  tlie  limits  of  a  single  term  of  study,  while  sacrificing  nothing  that  is  essential, 
and  nothing  that  is  usually  retained  from  the  study  of  the  larger  manuals  in  common 
use.  Thus  the  student  has  rare  opportunity  to  economize  his  time,  or  rather  to  employ 
that  which  he  has  to  the  best  advantage. 

A  notable  feature  is  the  author's  charming  "style,"  fortified  by  an  enthusiasm  over 
his  subject  in  which  the  student  will  not  fail  to  partake.  Believing  that  Natural 
Science  is  full  of  fascination,  he  has  moulded  it  into  a  form  that  attracts  the  attention 
and  kindles  the  enthusiasm  of  the  pupil. 

The  recent  editions  contain  the  author's  "  Practical  Questions  "  on  a  plan  never 
before  attempted  in  scientific  text-books.  These  are  questions  as  to  the  nature  and 
cause  of  common  phenomena,  and  are  not  directly  answered  in  the  text,  the  design 
being  to  test  and  promote  an  intelligent  use  of  the  student's  knowledge  of  the  foregoing 
principles. 

Steele's  Key  to  all  His  Works. 

This  work  is  mainly  composed  of  answers  to  the  Practical  Questions,  and  solutions  of  the 
problems,  in  the  author's  celebrated  "  Fourteen-Weeks  Courses  "  in  the  several  sciences, 
with  many  hints  to  teachers,  minor  tables,  &c.  Should  be  on  every  teacher's  desk. 

Prof.  J.  Dorman  Steele  is  an  indefatigable  student,  as  well  as  author,  and  his  books 
have  reached  a  fabulous  circulation.  It  is  safe  to  say  of  his  books  that  they  have 
accomplished  more  tangible  and  better  results  in  the  class-room  than  any  other  ever 
offered  to  American  schools,  and  have  been  translated  into  more  languages  for  foreign 
schools.  They  are  even  produced  in  raised  type  for  the  blind. 

32 


THE  NATIONAL   SERIES   OF  STANDARD   SCHOOL-BOOKS. 


THE   NEW   GANOT. 

Introductory  Course  of  Natural  Philosophy. 

This  book  was  originally  edited  from  Ganot's  "  Popular  Physics,"  by  William  G. 
Peck,  LL.D.,  Professor  of  Mathematics  and  Astronomy,  Columbia  College,  and  of 
Mechanics  in  the  School  of  Mines.  It  has  recently  been  revised  by  Levi  S.  Bur- 
bank,  A.  M.,  late  Principal  of  Warren  Academy,  Woburn,  Mass.,  and  James  I.  Hanson, 
A.M.,  Principal  of  the  High  School,  Woburn,  Mass. 

Of  elementary  works  those  of  M.  Ganot  stand  pre-eminent,  not  only  as  popular 
treatises,  but  as  thoroughly  scientific  expositions  of  the  principles  of  Physics.  His 
"  Traite  de  Physique  "  has  not  only  met  with  unprecedented  success  in  France,  but  has 
been  extensively  used  in  the  preparation  of  the  best  works  on  Physics  that  have  been 
issued  from  the  American  press. 

In  addition  to  the  "Traite  de  Physique,"  which  is  intended  for  the  use  of  colleges 
and  higher  institutions  of  learning,  M.  Ganot  published  this  more  elementary  work, 
adapted  to  the  use  of  schools  and  academies,  in  which  he  faithfully  preserved  the 
prominent  features  and  all  the  scientific  accuracy  of  the  larger  work.  It  is  charcter- 
ized  by  a  well-balanced  distribution  of  subjects,  a  logical  development  of  scientific 
principles,  and  a  remarkable  clearness  of  definition  and  explanation.  In  addition,  it  is 
profusely  illustrated  with  beautifully  executed  engravings,  admirably  calculated  to 
convey  to  the  mind  of  the  student  a  clear  conception  of  the  principles  unfolded.  Their 
completeness  and  accuracy  are  such  as  to  enable  the  teacher  to  dispense  with  much  of 
the  apparatus  usually  employed  in  teaching  the  elements  of  Physical  Science. 

After  several  years  of  great  popularity  the  American  publishers  have  brought  this 
important  book  thoroughly  up  to  the  times.  The  death  of  the  accomplished  educator, 
Professor  Burbank,  took  place  before  he  had  completed  his  work,  and  it  was  then 
taken  in  hand  by  his  friend,  Professor  Hanson,  who  was  familiar  with  his  plans,  and 
has  ably  and  satisfactorily  brought  the  work  to  completion. 

The  essential  characteristics  and  general  plan  of  the  book  have,  so  far  as  possible, 
been  retained,  but  at  the  same  time  many  parts  have  been  entirely  rewritten,  much 
new  matter  added,  a  large  number  of  new  cuts  introduced,  and  the  whole  treatise 
thoroughly  revised  and  brought  into  harmony  with  the  present  advanced  stage  of  sci- 
entific discovery. 

Among  the  new  features  designed  to  aid  in  teaching  the  subject-matter  are  the 
summaries  of  topics,  which,  it  is  thought,  will  be  found  very  convenient  in  short 
reviews. 

As  many  teachers  prefer  to  prepare  their  own  questions  on  the  text,  and  many  do  not 
have  time  to  spend  in  the  solution  of  pi-oblems,  it  has  been  deemed  expedient  to  insert 
both  the  review  questions  and  problems  at  the  end  of  the  volume,  to  be  used  or  not  at 
the  discretion  of  the  instructor. 


From  the  Churchman. 

"  No  department  of  science  has  under- 
gone so  many  improvements  and  changes 
in  the  last  quarter  of  a  century  as  that  of 
natural  philosophy.  So  many  and  so  im- 
portant have  been  the  discoveries  and 
inventions  in  every  branch  of  it  that 
everything  seems  changed  but  its  funda- 
mental principles.  Ganot  has  chapter 
upon  chapter  upon  subjects  that  were  not 
so  much  as  known  by  name  to  Olmsted  ; 
and  here  we  have  Ganot,  first  edited  by 
Professor  Peck,  and  afterward  revised  by 
the  late  Mr.  Burbank  and  Mr.  Hanson.  No 
elementary  works  upon  philosophy  have 
been  superior  to  those  of  Ganot,  either  as 
popular  treatises  or  as  scientific  exposi- 
tions of  the  principles  of  physics,  and 
his  '  Traite  de  Physique '  has  not  only  had 
a  great  success  in  France,  but  has  been 
freely  used  in  this  country  in  the  prepa- 
ration of  American  books  upon  the  sub- 


jects of  which  it  treats.  That  work  was 
intended  for  higher  institutions  of  learn- 
ing, and  Mr.  Ganot  prepared  a  more 
elementary  work  for  schools  and  acade- 
mies. It  is  as  scientifically  accurate  as 
the  larger  work,  and  is  characterized  by 
a  logical  development  of  scientific  princi- 
ples, by  clearness  of  definition  and  expla- 
nation, by  a  proper  distribution  of  sub- 
jects, and  by  its  admirable  engravings. 
We  here  have  Ganot's  work  enhanced  in 
value  by  the  labors  of  Professor  Peck  and  of 
Messrs.  Burbank  and  Hanson,  and  brought 
up  to  our  own  times.  The  essential  char- 
acteristics of  Ganot's  work  have  been  re- 
tained, but  much  of  the  book  has  been 
rewritten,  and  many  new  cuts  have  been 
introduced,  made  necessary  by  the  prog- 
ress of  scientific  discovery.  The  short 
reviews,  the  questions  on  the  text,  and 
the  problems  given  for  solution  are  desir- 
able additions  to  a  work  of  this  kind,  and 
will  give  the  book  increased  popularity. " 


14  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 

EARTH  SCIENCES  LIBRA 

This  book  is  due  on  the  last  date  stamped  below,  or 

on  the  date  to  which  renewed. 
Renewed  books  are  subject  to  immediate  recall. 


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